criyle/codenet-compile-errors huggingface dataset:
Language: C++

#include <stdio.h>

int main(void)
{
    int n, m, l;
    scanf("%d %d %d", &n, &m, &l);
    
    int32_t a[n][m], b[m][l], c[n][l];
    int i, j, k;
    
    /*init*/
    for (i = 0; i < n; ++i) {
        for (j = 0; j < m; ++j) {
            scanf("%ld", &a[i][j]);
        }
    }
    
    for (i = 0; i < m; ++i) {
        for (j = 0; j < l; ++j) {
            scanf("%ld", &b[i][j]);
        }
    }
    
    for (i = 0; i < n; ++i) {
        for (j = 0; j < l; ++j) {
            c[i][j] = 0;
        }
    }
    
    /*calc*/
    for (i = 0; i < n; ++i) {
        for (j = 0; j < l; ++j) {
            for (k = 0; k < m; ++k) {
                c[i][j] += a[i][k] * b[k][j];
            }
        }
    }
    
    /*output*/
    for (i = 0; i < n; ++i) {
        for (j = 0; j < l; ++j) {
            printf("%ld", c[i][j]);
            if (j < l - 1) printf(" ");
        }
        printf("\n");
    }
    
    return 0;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:8:5: error: 'int32_t' was not declared in this scope
    8 |     int32_t a[n][m], b[m][l], c[n][l];
      |     ^~~~~~~
a.cc:2:1: note: 'int32_t' is defined in header '<cstdint>'; this is probably fixable by adding '#include <cstdint>'
    1 | #include <stdio.h>
  +++ |+#include <cstdint>
    2 | 
a.cc:14:27: error: 'a' was not declared in this scope
   14 |             scanf("%ld", &a[i][j]);
      |                           ^
a.cc:20:27: error: 'b' was not declared in this scope
   20 |             scanf("%ld", &b[i][j]);
      |                           ^
a.cc:26:13: error: 'c' was not declared in this scope
   26 |             c[i][j] = 0;
      |             ^
a.cc:34:17: error: 'c' was not declared in this scope
   34 |                 c[i][j] += a[i][k] * b[k][j];
      |                 ^
a.cc:34:28: error: 'a' was not declared in this scope
   34 |                 c[i][j] += a[i][k] * b[k][j];
      |                            ^
a.cc:34:38: error: 'b' was not declared in this scope
   34 |                 c[i][j] += a[i][k] * b[k][j];
      |                                      ^
a.cc:42:27: error: 'c' was not declared in this scope
   42 |             printf("%ld", c[i][j]);
      |                           ^
Language: C++

#include<stdio.h>
int main(){
int x,y,z,zz;
long w;
int p[100][100];
int q[100][100];
int c[100][100];

for(int i=0;i<100;i++){
for(int j=0;j<100;j++){
p[i][j]=0;
q[i][j]=0;
c[i][j]=0;
}}
scanf("%d",&x);scanf("%d",&y);scanf("%d",&z);
for(int i=0;i<x;i++){
for(int j=0;j<y;j++){
scanf("%d",&zz);p[i][j]=zz;
}}
for(int i=0;i<y;i++){
for(int j=0;j<z;j++){
scanf("%d",&zz);q[i][j]=zz;
}}
w=0;
for(int i=0;i<x;i++){
for(int j=0;j<z;j++){
for(int k=0;k<y;k++){
c[i][j]=p[i][k]*q[k][j];
}
if(j<z-1)printf("%d ",c[i]j]);
else if(j==z-1)printf("%ld\n",c[i][j]);
w=0;
}
}
return 0;

}

Compiler output:
a.cc: In function 'int main()':
a.cc:30:27: error: expected ')' before 'j'
   30 | if(j<z-1)printf("%d ",c[i]j]);
      |                ~          ^
      |                           )
Language: C++

#include <iostream>
#include <cstdio>
#include <cstring>

using namespace std;

void DEBUGPrint(int ary[][100], int row, int col)
{
	printf("*DEBUG:BEGIN*********\n");
	for (int i = 0; i < row; i++)
	{
		for (int j = 0; j < col; j++)
		{
			if (j == col-1)
				printf("%d\n", ary[i][j]);
			else
				printf("%d ", ary[i][j]);
		}
	}
	printf("*DEBUG:END *********\n");
}
void Print(int ary[][100], int row, int col)
{
	for (int i = 0; i < row; i++)
	{
		for (int j = 0; j < col; j++)
		{
			if (j == col-1)
				printf("%d\n", ary[i][j]);
			else
				printf("%d ", ary[i][j]);
		}
	}
}

// ????´???????????????????????????°?????????????????????
int main()
{
	int n,m,l;
	int num;
	
	int A[101][101] = {0};
	int B[101][101] = {0};
	int C[101][101] = {0};
	scanf("%d %d %d", &n, &m, &l);
	
	for (int i = 0; i < n; i++)
	{
		for (int j = 0; j < m; j++)
		{
			int x;
			scanf("%d", &x);
			A[i][j] = x;
		}
	}
	//DEBUGPrint(A, n, m);
	
	for (int i = 0; i < m; i++)
	{
		for (int k = 0; k < l; k++)
		{
			int x;
			scanf("%d", &x);
			B[i][k] = x;
		}
	}
	//DEBUGPrint(B, n, m);
	
	//printf("n=%d, l=%d****\n", n, l);
	for (int i = 0; i < n; i++)
	{
		for (int j = 0; j < l; j++)
		{
			int sum = 0;
			for (int k = 0; k < m; k++)
			{
				sum += (A[i][k] * B[k][j]);
			}
			C[i][j] = sum;
			//printf("i,j=%d,%d\n", i,j);
		}
	}
	//DEBUGPrint(C, n, l);
	Print(C, n, l);
	
	
	return 0;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:84:15: error: cannot convert 'int (*)[101]' to 'int (*)[100]'
   84 |         Print(C, n, l);
      |               ^
      |               |
      |               int (*)[101]
a.cc:22:16: note:   initializing argument 1 of 'void Print(int (*)[100], int, int)'
   22 | void Print(int ary[][100], int row, int col)
      |            ~~~~^~~~~~~~~~
Language: C++

#include <iostream>
#include <cstdio>
#include <cstring>

using namespace std;

void DEBUGPrint(int ary[][101], int row, int col)
{
	printf("*DEBUG:BEGIN*********\n");
	for (int i = 0; i < row; i++)
	{
		for (int j = 0; j < col; j++)
		{
			if (j == col-1)
				printf("%d\n", ary[i][j]);
			else
				printf("%d ", ary[i][j]);
		}
	}
	printf("*DEBUG:END *********\n");
}
void Print(int ary[][100], int row, int col)
{
	for (int i = 0; i < row; i++)
	{
		for (int j = 0; j < col; j++)
		{
			if (j == col-1)
				printf("%d\n", ary[i][j]);
			else
				printf("%d ", ary[i][j]);
		}
	}
}

// ????´???????????????????????????°?????????????????????
int main()
{
	int n,m,l;
	int num;
	
	int A[101][101] = {0};
	int B[101][101] = {0};
	int C[101][101] = {0};
	scanf("%d %d %d", &n, &m, &l);
	
	for (int i = 0; i < n; i++)
	{
		for (int j = 0; j < m; j++)
		{
			int x;
			scanf("%d", &x);
			A[i][j] = x;
		}
	}
	//DEBUGPrint(A, n, m);
	
	for (int i = 0; i < m; i++)
	{
		for (int k = 0; k < l; k++)
		{
			int x;
			scanf("%d", &x);
			B[i][k] = x;
		}
	}
	//DEBUGPrint(B, n, m);
	
	//printf("n=%d, l=%d****\n", n, l);
	for (int i = 0; i < n; i++)
	{
		for (int j = 0; j < l; j++)
		{
			int sum = 0;
			for (int k = 0; k < m; k++)
			{
				sum += (A[i][k] * B[k][j]);
			}
			C[i][j] = sum;
			//printf("i,j=%d,%d\n", i,j);
		}
	}
	//DEBUGPrint(C, n, l);
	Print(C, n, l);
	
	
	return 0;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:84:15: error: cannot convert 'int (*)[101]' to 'int (*)[100]'
   84 |         Print(C, n, l);
      |               ^
      |               |
      |               int (*)[101]
a.cc:22:16: note:   initializing argument 1 of 'void Print(int (*)[100], int, int)'
   22 | void Print(int ary[][100], int row, int col)
      |            ~~~~^~~~~~~~~~
Language: C++

#include <iostream>
using namespace std;

int main(){
	int n, m, l, i, j, k;
	cin >> n >> m >> l;
	long a[n][m], b[m][l], c[n][l];
	for(i = 0; i <= n-1; i++){
		for(j = 0; j <= m-1; j++){
			cin >> a[i][j];
		}
	}
	for(i = 0; i <= m-1; i++){A
		for(j = 0; j <= l-1; j++){
			cin >> b[i][j];
		}
	}
	
	for(i = 0; i <= n-1; i++){   
		for(j = 0; j <= l-1; j++){
			c[i][j] = 0;
		}
	}
	
	for(i = 0; i <= n-1; i++){
		for(j = 0; j <= l-1; j++){
			for(k = 0; k <= m-1; k++){
				c[i][j] += a[i][k]*b[k][j];
			}
		}
	}
	
	for(i = 0; i <= n-1; i++){
		for(j = 0; j <= l-2; j++){
			cout << c[i][j] << ' ';
		}
		cout << c[i][l-1] << endl;
	}
	
	return 0;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:13:35: error: 'A' was not declared in this scope
   13 |         for(i = 0; i <= m-1; i++){A
      |                                   ^
a.cc:14:41: error: expected ';' before ')' token
   14 |                 for(j = 0; j <= l-1; j++){
      |                                         ^
      |                                         ;
Language: C++

#include <iostream>
using namespace std;

int main(){
	int n, m, l, i, j, k;
	cin >> n >> m >> l;
	long int a[n][m], b[m][l], c[n][l];
	for(i = 0; i <= n-1; i++){
		for(j = 0; j <= m-1; j++){
			cin >> a[i][j];
		}
	}
	for(i = 0; i <= m-1; i++){A
		for(j = 0; j <= l-1; j++){
			cin >> b[i][j];
		}
	}
	
	for(i = 0; i <= n-1; i++){   
		for(j = 0; j <= l-1; j++){
			c[i][j] = 0;
		}
	}
	
	for(i = 0; i <= n-1; i++){
		for(j = 0; j <= l-1; j++){
			for(k = 0; k <= m-1; k++){
				c[i][j] += a[i][k]*b[k][j];
			}
		}
	}
	
	for(i = 0; i <= n-1; i++){
		for(j = 0; j <= l-2; j++){
			cout << c[i][j] << ' ';
		}
		cout << c[i][l-1] << endl;
	}
	
	return 0;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:13:35: error: 'A' was not declared in this scope
   13 |         for(i = 0; i <= m-1; i++){A
      |                                   ^
a.cc:14:41: error: expected ';' before ')' token
   14 |                 for(j = 0; j <= l-1; j++){
      |                                         ^
      |                                         ;
Language: C++

import java.io.*;
import java.util.*;

public class Main {
    void run() {
        int N = readInt();
        int M = readInt();
        int L = readInt();
        int[][] A = new int[N][M];
        for (int i = 0; i < N; i++) {
            for (int j = 0; j < M; j++) {
                A[i][j] = readInt();
            }
        }
        int[][] B = new int[M][L];
        for (int i = 0; i < M; i++) {
            for (int j = 0; j < L; j++) {
                B[i][j] = readInt();
            }
        }
        int[][] C = new int[N][L];
        for (int i = 0; i < N; i++) {
            for (int j = 0; j < L; j++) {
                for (int k = 0; k < M; k++) {
                    C[i][j] += A[i][k] * B[k][j];
                }
            }
        }
        for (int i = 0; i < N; i++) {
            for (int j = 0; j < L; j++) {
                if (j > 0) sysout.print(' ');
                sysout.print(C[i][j]);
            }
            sysout.println();
        }
    }

    public static void main(String[] args) {
        new Main().run();
    }

    // flush automatically iff you call `println` or `printf` or `format`.
    PrintWriter sysout = new PrintWriter(System.out, true);

    BufferedReader in = new BufferedReader(new InputStreamReader(System.in));
    StringTokenizer buffer = null;

    String readLine() {
        buffer = null;
        try {
            return in.readLine();
        } catch (IOException e) {
            throw new RuntimeException(e);
        }
    }

    String read() {
        if (buffer == null || !buffer.hasMoreTokens()) {
            buffer = new StringTokenizer(readLine());
        }
        return buffer.nextToken();
    }

    int readInt() {
        return Integer.parseInt(read());
    }

    long readLong() {
        return Long.parseLong(read());
    }

    double readDouble() {
        return Double.parseDouble(read());
    }
}

Compiler output:
a.cc:1:1: error: 'import' does not name a type
    1 | import java.io.*;
      | ^~~~~~
a.cc:1:1: note: C++20 'import' only available with '-fmodules-ts'
a.cc:2:1: error: 'import' does not name a type
    2 | import java.util.*;
      | ^~~~~~
a.cc:2:1: note: C++20 'import' only available with '-fmodules-ts'
a.cc:4:1: error: expected unqualified-id before 'public'
    4 | public class Main {
      | ^~~~~~
Language: C++

#include<iostream>
using namespace std;

int main(void){
	int n,m,l;
	int work = 0;
	cin >> n >> m >> l;
	int matrixa[n][m];
	int matrixb[m][l];
	int matrixc[n][l];

	for(int i = 0; i < n; i++){
		for(int j = 0; j < m; j++){
			cin >> matrixa[i][j];
		}
	}
	for(int i = 0; i < m; i++){
		for(int j = 0; j < l; j++){
			cin >> matrixb[i][j];
		}
	}
	for(int i = 0; i < n; i++){
		for(int j = 0; j < l; j++){
			work = 0;
			for(int k = 0; k < m; k++){
				 work += matrixa[i][k] * matrixb[k][i]
			}
				
			matrixc[i][j] = work;
		}
	}

	for(int i = 0; i < n; i++){
		for(int j = 0; j < l; j++){
			cout << matrixc[i][j];
			if(!(j == l - 1)){
				cout << " ";
			}
		}
		cout << endl;
	}

	return 0;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:26:71: error: expected ';' before '}' token
   26 |                                  work += matrixa[i][k] * matrixb[k][i]
      |                                                                       ^
      |                                                                       ;
   27 |                         }
      |                         ~
Language: C++

#include<iostream>
using namespace std;

int main(){
	int n, m, l;
	int A[100][100], B[100][100], C[100][100];
	cin >> n >> m >>l;
	for(int i = 0; i < n; i++){
		for(int j = 0; j < m; j++) cin >> A[i][j];
	}
	for(int i = 0; i < m; i++){
		for(int j = 0; j < l; j++) cin >> B[i][j];
	}
	for(int i = 0; i < n; i++){
		for(int j = 0; j < l; j++){
			C[i][j] = 0;
			for(int k = 0; k < m; k++) C[i][j] += A[i[k] * B[k][j];
		}
	}
	for(int i = 0; i < n; i++){
		for(int j = 0; j < l; j++){
			cout << C[i][j] ;
		}
		cout << endl;
	}

	return 0;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:17:66: error: invalid types 'int[int]' for array subscript
   17 |                         for(int k = 0; k < m; k++) C[i][j] += A[i[k] * B[k][j];
      |                                                                  ^
a.cc:17:79: error: expected ']' before ';' token
   17 |                         for(int k = 0; k < m; k++) C[i][j] += A[i[k] * B[k][j];
      |                                                                               ^
      |                                                                               ]
Language: C++

#include <iostream>

using namespace std;

int main() {
    int n,m,l;
    cin >> n >> m >> l;

    int a[n][m];
    int b[m][l];
    memset(a, 0, sizeof(int) * n * m);
    memset(b, 0, sizeof(int) * m * l);

    for (int i = 0; i < n; i++) {
        for (int j = 0; j < m; j++) {
            int in;
            cin >> in;
            a[i][j] = in;
        }
    }
    for (int i = 0; i < m; i++) {
        for (int j = 0; j < l; j++) {
            int in;
            cin >> in;
            b[i][j] = in;
        }
    }

    for (int i = 0; i < n; i++) {
        for (int j = 0; j < l; j++) {
            int sum = 0;
            for (int k = 0; k < m; k ++) {
                sum += a[i][k] * b[k][j];
            }
            cout << sum;
            if (j < l-1)
                cout << " ";
        }
        cout << endl;
    }

    return 0;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:11:5: error: 'memset' was not declared in this scope
   11 |     memset(a, 0, sizeof(int) * n * m);
      |     ^~~~~~
a.cc:2:1: note: 'memset' is defined in header '<cstring>'; this is probably fixable by adding '#include <cstring>'
    1 | #include <iostream>
  +++ |+#include <cstring>
    2 |
Language: C++

#include <iostream>
using namespace std;

int main() {
	int n, m, l, A[100][100], B[100][100];
	long long int C[100][100];
	for (int i = 0;i < 100;i++) {
		for (int j = 0;j < 100;j++) {
			A[i][j] = 0;
			B[i][j] = 0;
			C[i][j] = 0;
		}
	}

	cin >> n >> m >> l;

	for (int i = 0;i < n;i++) {
		for (int j = 0;j < m;j++) {
			cin >> A[i][j];
		}
	}
	for (int i = 0;i < m;i++) {
		for (int j = 0;j < l;j++) {
			cin >> B[i][j];
		}
	}

	for (int i = 0;i < n;i++) {
		for (int j = 0;j < l;j++) {
			for (int k = 0;k < m;k++) {
				C[i][j] += A[i][k] * B[k][j];
			}
		}
	}

	for (int i=0;i < n;i++) {
		for (int j = 0;j < l;j++) {
			cout << C[i][j];
			if (j != l - 1)
				cout << " ";
		}
		cout << endl;
	}

	return 0;

Compiler output:
a.cc: In function 'int main()':
a.cc:45:18: error: expected '}' at end of input
   45 |         return 0;
      |                  ^
a.cc:4:12: note: to match this '{'
    4 | int main() {
      |            ^
Language: C++

(n, m, l) = [int(i) for i in input().split()]
A = []
for nc in range(n): 
    A.append([int(i) for i in input().split()])
B = []
for mc in range(m): 
    B.append([int(i) for i in input().split()])

product = [[0 for d in range(l)] for dd in range(n)]
      
for nc in range(n):
    for lc in range(l): 
        for mc in range(m):
            product[nc][lc] += A[nc][mc] * B[mc][lc] 

for r in product: 
    print(' '.join([str(d) for d in r]))

Compiler output:
a.cc:1:3: error: expected ')' before ',' token
    1 | (n, m, l) = [int(i) for i in input().split()]
      | ~ ^
      |   )
a.cc:1:6: error: expected constructor, destructor, or type conversion before ',' token
    1 | (n, m, l) = [int(i) for i in input().split()]
      |      ^
a.cc:1:9: error: expected constructor, destructor, or type conversion before ')' token
    1 | (n, m, l) = [int(i) for i in input().split()]
      |         ^
Language: C++

include<iostream>
using namespace std;

int main(){
 int n, m, l;
    long long A[100][100], B[100][100], C[100][100];
    
    cin >> n >> m >> l;
    for ( int i = 0; i < n; i++ )
      for ( int j = 0; j < m; j++ ) cin >> A[i][j];
    for ( int i = 0; i < m; i++ )
      for ( int j = 0; j < l; j++ ) cin >> B[i][j];
        
        for ( int i = 0; i < n; i++){
        for ( int j = 0; j < l; j++){
          C[i][j] = 0;
            for ( int k = 0; k < m; k++ ){
              C[i][j] += A[i][k]*B[k][j];
            }
        }
    }
    
    for ( int i = 0; i < n; i++ ){
        for ( int j = 0; j < l; j++){
          if ( j ) cout << " ";
        cout << C[i][j];
        }
        cout << endl;
    }
    
    
    
    return 0;
}   

Compiler output:
a.cc:1:1: error: 'include' does not name a type
    1 | include<iostream>
      | ^~~~~~~
a.cc: In function 'int main()':
a.cc:8:5: error: 'cin' was not declared in this scope
    8 |     cin >> n >> m >> l;
      |     ^~~
a.cc:25:20: error: 'cout' was not declared in this scope
   25 |           if ( j ) cout << " ";
      |                    ^~~~
a.cc:26:9: error: 'cout' was not declared in this scope
   26 |         cout << C[i][j];
      |         ^~~~
a.cc:28:9: error: 'cout' was not declared in this scope
   28 |         cout << endl;
      |         ^~~~
a.cc:28:17: error: 'endl' was not declared in this scope
   28 |         cout << endl;
      |                 ^~~~
Language: C++

#include<iostream>
#include<cstring>
using namespace std;

int main(){
const int MAX_N=500;
int n,m,l,a[MAX_N][MAX_N],b[MAX_N][MAX_N],Ans[MAX_N][MAX_N];
memset(Ans,0,sizeof(Ans));
cin>>n>>m>>l;
for(int i=1;i<=n;i++){
for(int j=1;j<=m;j++){
cin>>a[i][j];
}
}
for(int i=1;i<=m;i++){
for(int j=1;j<=l;j++){
cin>>b[i][j];
}
}
for(int i=1;i<=n;i++){
for(int j=1;j<=l;j++){
for(int k=1;k<=m;k++){
Ans += a[i][k]*b[k][j];
}
}
}
for(int i=1;i<=n;i++){
for(int j=1;j<=l;j++){
if(l==j){
cout<<Ans[i][j]<<endl;
}
else{
cout<<Ans[i][j]<<' ';
}
}
}
return 0;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:23:5: error: incompatible types in assignment of 'int' to 'int [500][500]'
   23 | Ans += a[i][k]*b[k][j];
      | ~~~~^~~~~~~~~~~~~~~~~~
Language: C++

#include<iostream>
using namespace std;

int main(){
 int n,m,l;
 int a[100][100],b[100][100],c[100][100];

 cin >> n >> m >> l;

 for(int i = 0; i < 100; i++){
  for(int j = 0; j < 100; j++){
   a[i][j] = 0;
   b[i][j] = 0;
  }
 }

 for(int i = 0; i < n; i++){
  for(int j = 0; j < m; j++){
   cin >> a[i][j];
  }
 }

 for(int i = 0; i < m; i++){
  for(int j = 0; j < l; j++){
   cin >> b[i][j];
  }
 }

 for(int i = 0; i < n; i++){
  for(int j = 0; j < l; j++){
   for(int k = 0; k < m; k++){
    c[i][j] += a[i][k] * b[k][[j];
   }
   if(j != 1) cout << " ";

   cout << c[i][j];
  }
  cout << endl;
 }
 

 return 0;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:32:30: error: two consecutive '[' shall only introduce an attribute before '[' token
   32 |     c[i][j] += a[i][k] * b[k][[j];
      |                              ^
Language: C++

#include<iostream>
using namespace std;

int main(){
 int n,m,l;
 long long a[100][100],b[100][100],c[100][100];

 cin >> n >> m >> l;

 for(int i = 0; i < 100; i++){
  for(int j = 0; j < 100; j++){
   a[i][j] = 0;
   b[i][j] = 0;
  }
 }

 for(int i = 0; i < n; i++){
  for(int j = 0; j < m; j++){
   cin >> a[i][j];
  }
 }

 for(int i = 0; i < m; i++){
  for(int j = 0; j < l; j++){
   cin >> b[i][j];
  }
 }

 for(int i = 0; i < n; i++){
  for(int j = 0; j < l; j++){
   c[i][j] = 0;
   for(int k = 0; k < m; k++){
    c[i][j] += a[i][k] * b[k][[j];
   }
   if(j != 1) cout << " ";

   cout << c[i][j];
  }
  cout << endl;
 }
 

 return 0;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:33:30: error: two consecutive '[' shall only introduce an attribute before '[' token
   33 |     c[i][j] += a[i][k] * b[k][[j];
      |                              ^
Language: C++

 int a[n][m];
 int b[m][l];
 int c [n][l];

 for (int i = 0; i < n; i++) {
   for (int j = 0; j < m; j++) {
     cin >> a[i][j];
   }
 }
 for (int i = 0; i < m; i++) {
   for (int j = 0; j < l; j++) {
     cin >> b[i][j];
   }
 }

 for (int i = 0; i < n; i++) { 
   for (int j = 0; j < l; j++) {
     c[i][j] = 0;    
     for (int k = 0; k < m; k++) {
       c[i][j] += a[i][k] * b[k][j]; 
     }
   }
 }

 for (int i = 0; i < n; i++) {
  for (int j = 0; j < l; j++) {
    if (j != 0) cout << " ";
    cout << c[i][j];
  }
  cout << endl;
 }

}

Compiler output:
a.cc:1:8: error: 'n' was not declared in this scope
    1 |  int a[n][m];
      |        ^
a.cc:1:11: error: 'm' was not declared in this scope
    1 |  int a[n][m];
      |           ^
a.cc:2:8: error: 'm' was not declared in this scope
    2 |  int b[m][l];
      |        ^
a.cc:2:11: error: 'l' was not declared in this scope
    2 |  int b[m][l];
      |           ^
a.cc:3:9: error: 'n' was not declared in this scope
    3 |  int c [n][l];
      |         ^
a.cc:3:12: error: 'l' was not declared in this scope
    3 |  int c [n][l];
      |            ^
a.cc:5:2: error: expected unqualified-id before 'for'
    5 |  for (int i = 0; i < n; i++) {
      |  ^~~
a.cc:5:18: error: 'i' does not name a type
    5 |  for (int i = 0; i < n; i++) {
      |                  ^
a.cc:5:25: error: 'i' does not name a type
    5 |  for (int i = 0; i < n; i++) {
      |                         ^
a.cc:10:2: error: expected unqualified-id before 'for'
   10 |  for (int i = 0; i < m; i++) {
      |  ^~~
a.cc:10:18: error: 'i' does not name a type
   10 |  for (int i = 0; i < m; i++) {
      |                  ^
a.cc:10:25: error: 'i' does not name a type
   10 |  for (int i = 0; i < m; i++) {
      |                         ^
a.cc:16:2: error: expected unqualified-id before 'for'
   16 |  for (int i = 0; i < n; i++) {
      |  ^~~
a.cc:16:18: error: 'i' does not name a type
   16 |  for (int i = 0; i < n; i++) {
      |                  ^
a.cc:16:25: error: 'i' does not name a type
   16 |  for (int i = 0; i < n; i++) {
      |                         ^
a.cc:25:2: error: expected unqualified-id before 'for'
   25 |  for (int i = 0; i < n; i++) {
      |  ^~~
a.cc:25:18: error: 'i' does not name a type
   25 |  for (int i = 0; i < n; i++) {
      |                  ^
a.cc:25:25: error: 'i' does not name a type
   25 |  for (int i = 0; i < n; i++) {
      |                         ^
a.cc:33:1: error: expected declaration before '}' token
   33 | }
      | ^
Language: C++

#include <iostream>
using namespace std;

 int a[n][m];
 int b[m][l];
 int c [n][l];

 for (int i = 0; i < n; i++) {
   for (int j = 0; j < m; j++) {
     cin >> a[i][j];
   }
 }
 for (int i = 0; i < m; i++) {
   for (int j = 0; j < l; j++) {
     cin >> b[i][j];
   }
 }

 for (int i = 0; i < n; i++) { 
   for (int j = 0; j < l; j++) {
     c[i][j] = 0;    
     for (int k = 0; k < m; k++) {
       c[i][j] += a[i][k] * b[k][j]; 
     }
   }
 }

 for (int i = 0; i < n; i++) {
  for (int j = 0; j < l; j++) {
    if (j != 0) cout << " ";
    cout << c[i][j];
  }
  cout << endl;
 }

}

Compiler output:
a.cc:4:8: error: 'n' was not declared in this scope
    4 |  int a[n][m];
      |        ^
a.cc:4:11: error: 'm' was not declared in this scope; did you mean 'tm'?
    4 |  int a[n][m];
      |           ^
      |           tm
a.cc:5:8: error: 'm' was not declared in this scope; did you mean 'tm'?
    5 |  int b[m][l];
      |        ^
      |        tm
a.cc:5:11: error: 'l' was not declared in this scope
    5 |  int b[m][l];
      |           ^
a.cc:6:9: error: 'n' was not declared in this scope
    6 |  int c [n][l];
      |         ^
a.cc:6:12: error: 'l' was not declared in this scope
    6 |  int c [n][l];
      |            ^
a.cc:8:2: error: expected unqualified-id before 'for'
    8 |  for (int i = 0; i < n; i++) {
      |  ^~~
a.cc:8:18: error: 'i' does not name a type
    8 |  for (int i = 0; i < n; i++) {
      |                  ^
a.cc:8:25: error: 'i' does not name a type
    8 |  for (int i = 0; i < n; i++) {
      |                         ^
a.cc:13:2: error: expected unqualified-id before 'for'
   13 |  for (int i = 0; i < m; i++) {
      |  ^~~
a.cc:13:18: error: 'i' does not name a type
   13 |  for (int i = 0; i < m; i++) {
      |                  ^
a.cc:13:25: error: 'i' does not name a type
   13 |  for (int i = 0; i < m; i++) {
      |                         ^
a.cc:19:2: error: expected unqualified-id before 'for'
   19 |  for (int i = 0; i < n; i++) {
      |  ^~~
a.cc:19:18: error: 'i' does not name a type
   19 |  for (int i = 0; i < n; i++) {
      |                  ^
a.cc:19:25: error: 'i' does not name a type
   19 |  for (int i = 0; i < n; i++) {
      |                         ^
a.cc:28:2: error: expected unqualified-id before 'for'
   28 |  for (int i = 0; i < n; i++) {
      |  ^~~
a.cc:28:18: error: 'i' does not name a type
   28 |  for (int i = 0; i < n; i++) {
      |                  ^
a.cc:28:25: error: 'i' does not name a type
   28 |  for (int i = 0; i < n; i++) {
      |                         ^
a.cc:36:1: error: expected declaration before '}' token
   36 | }
      | ^
Language: C++

include <iostream>
using namespace std;

int a[101][101] = {0},b[101][101] = {0},c[101][101] = {0};

int main()
{
	int n, m, l;
	cin >> n >> m >> l;

	for(int i = 0; i < n; i++){
		for(int j = 0; j < m; j++){
			cin >> a[i][j];
		}
	}
	for(int i = 0; i < m; i++){
		for(int j = 0; j < l; j++){
			cin >> b[i][j];
		}
	}

	for(int i = 0; i < n; i++){
		for(int j = 0; j < l; j++){
			for(int k = 0; k < m; k++){
			c[i][j] += a[i][k] * b[k][j];
			}
		}
	}

	for(int i = 0; i < n; i++){
		for(int j = 0; j < l; j++){
			cout << c[i][j];
			if(j < l - 1){
				cout << ' ';
			}
		}
		cout << endl;
	}

	return 0;
}

Compiler output:
a.cc:1:1: error: 'include' does not name a type
    1 | include <iostream>
      | ^~~~~~~
a.cc: In function 'int main()':
a.cc:9:9: error: 'cin' was not declared in this scope
    9 |         cin >> n >> m >> l;
      |         ^~~
a.cc:32:25: error: 'cout' was not declared in this scope
   32 |                         cout << c[i][j];
      |                         ^~~~
a.cc:37:17: error: 'cout' was not declared in this scope
   37 |                 cout << endl;
      |                 ^~~~
a.cc:37:25: error: 'endl' was not declared in this scope
   37 |                 cout << endl;
      |                         ^~~~
Language: C++


#include <iostream>
using namespace std;

int main()
{

	int a[100][100] = {0},b[100][100] = {0},
	long c[100][100] = {0};

	int n, m, l;
	cin >> n >> m >> l;

	for(int i = 0; i < n; i++){
		for(int j = 0; j < m; j++){
			cin >> a[i][j];
		}
	}

	for(int i = 0; i < m; i++){
		for(int j = 0; j < l; j++){
			cin >> b[i][j];
		}
	}

	for(int i = 0; i < n; i++){
		for(int j = 0; j < l; j++){
			for(int k = 0; k < m; k++){
			c[i][j] += a[i][k] * b[k][j];
			}
		}
	}

	for(int i = 0; i < n; i++){
		for(int j = 0; j < l; j++){
			cout <<  << c[i][j];
			if(j < l - 1){
				cout << ' ';
			}
		}
		cout << endl;
	}
	

	return 0;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:9:9: error: expected unqualified-id before 'long'
    9 |         long c[100][100] = {0};
      |         ^~~~
a.cc:29:25: error: 'c' was not declared in this scope
   29 |                         c[i][j] += a[i][k] * b[k][j];
      |                         ^
a.cc:36:34: error: expected primary-expression before '<<' token
   36 |                         cout <<  << c[i][j];
      |                                  ^~
a.cc:36:37: error: 'c' was not declared in this scope
   36 |                         cout <<  << c[i][j];
      |                                     ^
Language: C++


#include <iostream>
using namespace std;

int main()
{

	int a[100][100] = {0},b[100][100] = {0},
	long c[100][100] = {0};

	int n, m, l;
	cin >> n >> m >> l;

	for(int i = 0; i < n; i++){
		for(int j = 0; j < m; j++){
			cin >> a[i][j];
		}
	}

	for(int i = 0; i < m; i++){
		for(int j = 0; j < l; j++){
			cin >> b[i][j];
		}
	}

	for(int i = 0; i < n; i++){
		for(int j = 0; j < l; j++){
			for(int k = 0; k < m; k++){
			c[i][j] += a[i][k] * b[k][j];
			}
		}
	}

	for(int i = 0; i < n; i++){
		for(int j = 0; j < l; j++){
			cout << c[i][j];
			if(j < l - 1){
				cout << ' ';
			}
		}
		cout << endl;
	}
	

	return 0;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:9:9: error: expected unqualified-id before 'long'
    9 |         long c[100][100] = {0};
      |         ^~~~
a.cc:29:25: error: 'c' was not declared in this scope
   29 |                         c[i][j] += a[i][k] * b[k][j];
      |                         ^
a.cc:36:33: error: 'c' was not declared in this scope
   36 |                         cout << c[i][j];
      |                                 ^
Language: C++


#include <iostream>
using namespace std;

int main()
{

	int a[100][100] = {0},b[100][100] = {0};
	long sum = 0;

	int n, m, l;
	cin >> n >> m >> l;

	for(int i = 0; i < n; i++){
		for(int j = 0; j < m; j++){
			cin >> a[i][j];
		}
	}

	for(int i = 0; i < m; i++){
		for(int j = 0; j < l; j++){
			cin >> b[i][j];
		}
	}

	for(int i = 0; i < n; i++){
		for(int j = 0; j < l; j++){
			sum = 0;
			for(int k = 0; k < m; k++){
			sum += a[i][k] * b[k][j];
			}
			cout << sum;
			if(j < l - 1){
				cout << ' ';
			}
		}
		cout << endl;
	}
	re

Compiler output:
a.cc: In function 'int main()':
a.cc:39:9: error: 're' was not declared in this scope
   39 |         re
      |         ^~
a.cc:39:11: error: expected '}' at end of input
   39 |         re
      |           ^
a.cc:6:1: note: to match this '{'
    6 | {
      | ^
Language: C++

#include <iostream>
using namespace std;

int main(void){
		int n,m,l;
		cin >> n >> m >> l;
		int a[n][m];
		int b[m][l];
		int c[n][l];

		for(int i = 0;i < n;i++){
				for(int j = 0;j < m;j++){
						a[i][j] = 0;
				}
		}
		for(int i = 0;i < m;i++){
				for(int j = 0;j < l;j++){
						b[i][j] = 0;
				}
		}
		for(int i = 0;i < n;i++){
				for(int j = 0;j < l;j++){
						c[i][j] = 0;
				}
		}
		//配列へ入力
		
		for(int i = 0;i < n;i++){
				for(int j = 0;j < m;j++){
						cin >> a[i][j];
				}
		}
		for(int i = 0;i < m;i++){
				for(int j = 0;j < l;j++){
				cin >> b[i][j];
				}
		}
		//計算、出力
		for(int i = 0;i < n;i++){
				for(int j = 0;j < l;j++){
						for(int k = 0;k < m;k++){
								c[i][j] += a[i][k] * b[k][j];
						}
						cout << c[i][j];
　　　　　　　　　　　　　　　　　　　　　　　　if(j != l-1){
                                                                cout << " ";
                                                }
				}
				cout << endl;
		}
		return 0;
}
				
		

Compiler output:
a.cc:45:1: error: extended character 　 is not valid in an identifier
   45 | 　　　　　　　　　　　　　　　　　　　　　　　　if(j != l-1){
      | ^
a.cc:45:1: error: extended character 　 is not valid in an identifier
a.cc:45:1: error: extended character 　 is not valid in an identifier
a.cc:45:1: error: extended character 　 is not valid in an identifier
a.cc:45:1: error: extended character 　 is not valid in an identifier
a.cc:45:1: error: extended character 　 is not valid in an identifier
a.cc:45:1: error: extended character 　 is not valid in an identifier
a.cc:45:1: error: extended character 　 is not valid in an identifier
a.cc:45:1: error: extended character 　 is not valid in an identifier
a.cc:45:1: error: extended character 　 is not valid in an identifier
a.cc:45:1: error: extended character 　 is not valid in an identifier
a.cc:45:1: error: extended character 　 is not valid in an identifier
a.cc:45:1: error: extended character 　 is not valid in an identifier
a.cc:45:1: error: extended character 　 is not valid in an identifier
a.cc:45:1: error: extended character 　 is not valid in an identifier
a.cc:45:1: error: extended character 　 is not valid in an identifier
a.cc:45:1: error: extended character 　 is not valid in an identifier
a.cc:45:1: error: extended character 　 is not valid in an identifier
a.cc:45:1: error: extended character 　 is not valid in an identifier
a.cc:45:1: error: extended character 　 is not valid in an identifier
a.cc:45:1: error: extended character 　 is not valid in an identifier
a.cc:45:1: error: extended character 　 is not valid in an identifier
a.cc:45:1: error: extended character 　 is not valid in an identifier
a.cc:45:1: error: extended character 　 is not valid in an identifier
a.cc: In function 'int main()':
a.cc:45:1: error: '\U00003000\U00003000\U00003000\U00003000\U00003000\U00003000\U00003000\U00003000\U00003000\U00003000\U00003000\U00003000\U00003000\U00003000\U00003000\U00003000\U00003000\U00003000\U00003000\U00003000\U00003000\U00003000\U00003000\U00003000if' was not declared in this scope
   45 | 　　　　　　　　　　　　　　　　　　　　　　　　if(j != l-1){
      | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Language: C++

#include <iostream>
#include <iomanip>
using namespace std;

int main(){
	int n=0,m=0,l=0;
	int i=0,j=0,k=0;

	cin >> n >> m >> l;
	int A[n+1][m+1];
	int B[m+1][l+1];
	int C[n+1][l+1];
	// ?????????
	for(i=0;i<=n;i++){
		for(j=0;j<=m;j++){
			A[i][j]=0;
		}
	}
	for(i=0;i<=m;i++){
		for(j=0;j<=l;j++){
			B[i][j]=0;
		}
	}
	for(i=0;i<=n;i++){
		for(j=0;j<=l;j++){
			C[i][j]=0;
		}
	}

	// ????????????
	for(i=1;i<=n;i++){
		for(j=1;j<=m;j++){
			cin >> A[i][j];
		}
	}
	for(i=1;i<=m;i++){
		for(j=1;j<=l;j++){
			cin >> B[i][j];
		}
	}

	// ????????????
	for(i=1;i<=n;i++){
		for(j=1;j<=l;j++){
			for(k=1;k<=m;k++){
				C[i][l] += A[i][k]*B[k][j];
			}
		}
	}
	

	for(i=1;i<=n;i++){
		for(j=1;j<=m;j++){
			if(j==c+1){
				cout << C[i][j];
			}else{
			cout << A[i][j] << " ";
			}
		}
		cout << endl;
	}

return 0;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:54:31: error: 'c' was not declared in this scope
   54 |                         if(j==c+1){
      |                               ^
Language: C++

#include <iostream>
using namespace std;
int main(){
    int n,m,l;
    int A[100][100],B[100][100],C[100][100];
    cin>>n>>m>>l;

    //??????A
    int A[n][m];
    for (int i = 0; i < n ; ++i) {
        for (int j = 0; j < m ; ++j) {
            cin>>A[i][j];
        }
    }

    //??????B
    int B[m][l];
    for (int i = 0; i < m ; ++i) {
        for (int j = 0; j < l ; ++j) {
            cin >> B[i][j];
        }
    }

    //??????C
    int C[n][l];
    for (int i = 0; i < n ; ++i) {
        for (int j = 0; j < l ; ++j) {
            for (int k = 0; k < m ; ++k) {
                C[i][j] += A[i][k]*B[k][j];
            }
        }
    }
    //??????
    for (int i = 0; i < n ; ++i) {
        for (int j = 0; j < l-1  ; ++j) {
            cout<<C[i][j]<<" ";
        }
        cout << C[i][l-1] << endl;
    }
    return 0;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:9:9: error: conflicting declaration 'int A [n][m]'
    9 |     int A[n][m];
      |         ^
a.cc:5:9: note: previous declaration as 'int A [100][100]'
    5 |     int A[100][100],B[100][100],C[100][100];
      |         ^
a.cc:17:9: error: conflicting declaration 'int B [m][l]'
   17 |     int B[m][l];
      |         ^
a.cc:5:21: note: previous declaration as 'int B [100][100]'
    5 |     int A[100][100],B[100][100],C[100][100];
      |                     ^
a.cc:25:9: error: conflicting declaration 'int C [n][l]'
   25 |     int C[n][l];
      |         ^
a.cc:5:33: note: previous declaration as 'int C [100][100]'
    5 |     int A[100][100],B[100][100],C[100][100];
      |                                 ^
Language: C++

#include <iostream>
using namespace std;
int main(){
    int n,m,l;
    int A[100][100],B[100][100],C[100][100];
    cin>>n>>m>>l;

    //??????A
    for (int i = 0; i < n ; ++i) {
        for (int j = 0; j < m ; ++j) {
            cin>>A[i][j];
        }
    }

    //??????B
    for (int i = 0; i < m ; ++i) {
        for (int j = 0; j < l ; ++j) {
            cin >> B[i][j];
        }
    }

    //??????C
    for (int i = 0; i < n ; ++i) {
        for (int j = 0; j < l ; ++j) {
            for (int k = 0; k < m ; ++k) {
                C[i][j] += A[i][k]*B[k][j];
            }
        }
    }
    //??????
    for(int i=0;i<n;i++){
        for(int j=0;j<l;j++) 
        if(j)cout << " ";
        cout << C[i][j];
    }
    cout << endl;
    return 0;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:34:22: error: 'j' was not declared in this scope
   34 |         cout << C[i][j];
      |                      ^
Language: C++

#include<iostream>
#include<iomanip>
using namespace std;

int main(){
	int n,m,l;
	cin >> n >> m >> l;
	int a[n][m],b[m][l],c[n][l];
	for(i=0;i<n;i++){
		for(j=0;j<m;j++){
			cin >> a[i][j];
		}
	}
	for(i=0;i<m;i++){
		for(j=0;j<l;j++){
			cin >> b[i][j];
		}
	}
	for(i=0;i<n;i++){
		for(j=0;j<l;j++){
			c[i][j]=0;
			for(k=0;k<m;k++){
				c[i][j]=c[i][j]+a[i][k]*b[k][j];
			}
			cout << c[i][j] << " ";
		}
		cout << endl;
	}

}

Compiler output:
a.cc: In function 'int main()':
a.cc:9:13: error: 'i' was not declared in this scope
    9 |         for(i=0;i<n;i++){
      |             ^
a.cc:10:21: error: 'j' was not declared in this scope
   10 |                 for(j=0;j<m;j++){
      |                     ^
a.cc:14:13: error: 'i' was not declared in this scope
   14 |         for(i=0;i<m;i++){
      |             ^
a.cc:15:21: error: 'j' was not declared in this scope
   15 |                 for(j=0;j<l;j++){
      |                     ^
a.cc:19:13: error: 'i' was not declared in this scope
   19 |         for(i=0;i<n;i++){
      |             ^
a.cc:20:21: error: 'j' was not declared in this scope
   20 |                 for(j=0;j<l;j++){
      |                     ^
a.cc:22:29: error: 'k' was not declared in this scope
   22 |                         for(k=0;k<m;k++){
      |                             ^
Language: C++

#include<iostream>
#include<iomanip>
using namespace std;

int main(){
	int n,m,l;
	cin >> n >> m >> l;
	int a[n][m],b[m][l],c[n][l];
	for(int i=0;i<n;i++){
		for(int j=0;j<m;j++){
			cin >> a[i][j];
		}
	}
	for(i=0;i<m;i++){
		for(j=0;j<l;j++){
			cin >> b[i][j];
		}
	}
	for(i=0;i<n;i++){
		for(j=0;j<l;j++){
			c[i][j]=0;
			for(k=0;k<m;k++){
				c[i][j]=c[i][j]+a[i][k]*b[k][j]
			}
			cout << c[i][j] << " ";
		}
		cout << endl;
	}

}

Compiler output:
a.cc: In function 'int main()':
a.cc:14:13: error: 'i' was not declared in this scope
   14 |         for(i=0;i<m;i++){
      |             ^
a.cc:15:21: error: 'j' was not declared in this scope
   15 |                 for(j=0;j<l;j++){
      |                     ^
a.cc:19:13: error: 'i' was not declared in this scope
   19 |         for(i=0;i<n;i++){
      |             ^
a.cc:20:21: error: 'j' was not declared in this scope
   20 |                 for(j=0;j<l;j++){
      |                     ^
a.cc:22:29: error: 'k' was not declared in this scope
   22 |                         for(k=0;k<m;k++){
      |                             ^
Language: C++

#include<iostream>
#include<iomanip>
using namespace std;

int main(){
	int n,m,l;
	cin >> n >> m >> l;
	int a[n][m],b[m][l],c[n][l];
	for(int i=0;i<n;i++){
		for(int j=0;j<m;j++){
			cin >> a[i][j];
		}
	}
	for(int i=0;i<m;i++){
		for(int j=0;j<l;j++){
			cin >> b[i][j];
		}
	}
	for(int i=0;i<n;i++){
		for(int j=0;j<l;j++){
			c[i][j]=0;
			for(int k=0;k<m;k++){
				c[i][j]=c[i][j]+a[i][k]*b[k][j]
			}
			cout << c[i][j] << " ";
		}
		cout << endl;
	}

}

Compiler output:
a.cc: In function 'int main()':
a.cc:23:64: error: expected ';' before '}' token
   23 |                                 c[i][j]=c[i][j]+a[i][k]*b[k][j]
      |                                                                ^
      |                                                                ;
   24 |                         }
      |                         ~
Language: C++

#include <iostream>
using namespace std;
int main() {
  unsigned int n, m, l;
  cin >> n >> m >> l;

  unsigned nt **A = new unsigned int*[n];
  for (int i = 0; i < n; i++) {
    A[i] = new int[m];
  }

  unsigned int **B = new unsigned int*[m];
  for (int i = 0; i < m; i++) {
    B[i] = new int[l];
  }
  unsigned int **C = new unsigned int*[n];
  for (int i = 0; i < n; i++) {
    C[i] = new int[l];
  }

  for (int i = 0; i < n; i++) {
    for (int j = 0; j < m; j++) {
      A[i][j] = 0;
      cin >> A[i][j];
    }
  }

  for (int i = 0; i < m; i++) {
    for (int j = 0; j < l; j++) {
      B[i][j] = 0;
      cin >> B[i][j];
    }
  }

  for (int i = 0; i < n; i++) {
    for (int j = 0; j < l; j++) {
      C[i][j] = 0;
    }
  }

  for (int i = 0; i < n; i++) {
    for (int j = 0; j < l; j++) {
      for (int k = 0; k < m; k++) {
        C[i][j] += A[i][k] * B[k][j];
      }
    }
  }


  for (int i = 0; i < n; i++) {
    for (int j = 0; j < l; j++) {
      cout << C[i][j];
      if (j != l-1) {
        cout << " ";
      }
    }
    cout << endl;
  }

  delete [] A;
  delete [] B;
  delete [] C;
  return 0;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:7:15: error: expected initializer before '*' token
    7 |   unsigned nt **A = new unsigned int*[n];
      |               ^
a.cc:9:5: error: 'A' was not declared in this scope
    9 |     A[i] = new int[m];
      |     ^
a.cc:14:12: error: invalid conversion from 'int*' to 'unsigned int*' [-fpermissive]
   14 |     B[i] = new int[l];
      |            ^~~~~~~~~~
      |            |
      |            int*
a.cc:18:12: error: invalid conversion from 'int*' to 'unsigned int*' [-fpermissive]
   18 |     C[i] = new int[l];
      |            ^~~~~~~~~~
      |            |
      |            int*
a.cc:23:7: error: 'A' was not declared in this scope
   23 |       A[i][j] = 0;
      |       ^
a.cc:44:20: error: 'A' was not declared in this scope
   44 |         C[i][j] += A[i][k] * B[k][j];
      |                    ^
a.cc:60:13: error: 'A' was not declared in this scope
   60 |   delete [] A;
      |             ^
Language: C++

#include <stdio.h>
int n, m, l, a[100][100], b[100][100];
int main() {
	scanf("%d%d%d", &n, &m, &l);
	for(int i = 0; i < n; i++) {
		for(int j = 0; j < m; j++) {
			scanf("%d", &a[i][j]);
		}
	}
	for(int i = 0; i < m; i++) {
		for(int j = 0; j < l; j++) {
			scanf("%d", &b[i][j]);
		}
	}
	for(int i = 0; i < n; i++) {
		for(int j = 0; j < l; j++) {
			int ret = 0;
			for(int i = 0; i < m; i++) ret += a[i][k] * b[k][j];
			if(j) puts(" ");
			printf("%d", ret);
		}
		puts("\n");
	}
	return 0;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:18:64: error: 'k' was not declared in this scope
   18 |                         for(int i = 0; i < m; i++) ret += a[i][k] * b[k][j];
      |                                                                ^
Language: C++

n,m,l = gets.split(" ").map{|x| x.to_i}
l_mat =Array.new()
r_mat=Array.new()
n.times do |i|
    l_mat[i]=gets.split(" ").map{|x| x.to_i}
end
m.times do |i|
    r_mat[i]=gets.split(" ").map{|x| x.to_i}
end
ans_mat=Array.new()
n.times do |i|
    ans_mat[i]=Array.new(l)
    l.times do |j|
        ans_mat[i][j]=0
        m.times do |k|
            ans_mat[i][j]+=l_mat[i][k]*r_mat[k][j]
        end
    end
end
n.times do|i|
    l.times do |j|
        print(ans_mat[i][j]," ")
    end
    puts()
end

Compiler output:
a.cc:1:1: error: 'n' does not name a type
    1 | n,m,l = gets.split(" ").map{|x| x.to_i}
      | ^
a.cc:2:1: error: 'l_mat' does not name a type
    2 | l_mat =Array.new()
      | ^~~~~
a.cc:6:1: error: 'end' does not name a type
    6 | end
      | ^~~
a.cc:9:1: error: 'end' does not name a type
    9 | end
      | ^~~
Language: C++

#include <iostream>

const long N = 100;
const long M = 100;
const long L = 100;

long main(void) {
  long n = 0;
  long m = 0;
  long l = 0;

  long a[N][M] = {0};
  long b[M][L] = {0};
  long c[N][L] = {0};

  std::cin >> n >> m >> l;

  for (long i = 0; i < n; i++) {
    for (long j = 0; j < m; j++) {
      std::cin >> a[i][j];
    }
  }

  for (long i = 0; i < m; i++) {
    for (long j = 0; j < l; j++) {
      std::cin >> b[i][j];
    }
  }
  
  for (long i = 0; i < n; i++) {
    for (long j = 0; j < l; j++) {
      for (long k = 0; k < m; k++) {
	c[i][j] += (a[i][k] * b[k][j]);
      }

      std::cout << c[i][j];
      
      if (j < (l - 1)) {
      	std::cout << " ";
      }
    }
    
    std::cout << std::endl;
  }
      
  
  return 0;
}

Compiler output:
cc1plus: error: '::main' must return 'int'
Language: C++

#include <stdio.h>
#include <new>

int main(void)
{
  int n,m,l;
  int i,j,k;

  //n,m,l?????\???
  scanf("%d%d%d",&n,&m,&l);

  //A,B,C?????????????¢????
  int**A = new int*[n];
  for(i=0; i<n; i++){
    A[i] = new int[m];
  }

  int**B = new int*[m];
  for(i=0; i<m; i++){
    B[i] = new int[l];
  }

  long int**C = new long int*[n];
  for(i=0; i<n; i++){
    C[i] = new long int[l];
  }

  //C??????????????¨???0???
  for(i=0; i<n; i++){
    for(j=0; j<l; j++){
      C[i][j] = 0;
    }
  }
  
  //A,B?????\???
  for(i=0; i<n; i++){
    for(j=0; j<m; j++){
      scanf("%d",&A[i][j]);
    }
  }

  for(i=0; i<m; i++){
    for(j=0; j<l; j++){
      scanf("%d",&B[i][j]);
    }
  }
  
 
  //??????C????????????
  for(i=0; i<n; i++){
    for(j=0; j<l; j++){
      for(k=0; k<m; k++){
	C[i][j] = C[i][j] + (A[i][k] * B[k][j]);
      }
    }
  }

  //C?????????
  for(i=0; i<n; i++){
    for(j=0; j<l; j++){
      printf("%ld",C[i][j]);
      if(j==(l-1))
	puts("");
      else
	printf(" ");
    }
  }
  
  //?¢???????????????????????????????
  for(i=0; i<n; i++){
    delete[] A[i];
    delete[] C[i];
  }
  delete[] A;
  delete[] C;

  for(i=0; i<m; i++){
    delete[] B[i];
  }
  delete[] B;

  return(0);

Compiler output:
a.cc: In function 'int main()':
a.cc:82:13: error: expected '}' at end of input
   82 |   return(0);
      |             ^
a.cc:5:1: note: to match this '{'
    5 | {
      | ^
Language: C++

#include <iostream>
using namespace std;
???
int main(){
	
	int n,m;
	cin >> n >> m;
	int a[100][100];
	int b[100];
	int c[100];
???
	for(int i = 0; i < n; i++){
		for(int j = 0; j < m; j++){
			cin >> a[i][j];
		}
//		cout << endl;
	}
???
	for(int j = 0; j < m; j++){
		cin >> b[j];
//		cout << endl;
	}
???
	for(int i = 0; i < n; i++){
		c[i] = 0;
		for(int j = 0; j < m; j++){
			c[i] += a[i][j] * b[j];
		}
	}
???
	for(int i = 0; i < n; i++){
		cout << c[i] << endl;
	}
???
	return 0;
}

Compiler output:
a.cc:3:1: error: expected unqualified-id before '?' token
    3 | ???
      | ^
Language: C++

#include<iostream>
using namespace std;
??
int main(){
????????int n, m, l;
????????long long a[100][100], b[100][100], c[100][100];
??
????????cin >> n >> m >> l;
??
????????for (int i = 0; i < 100; i++){
????????????????for (int j = 0; j < 100; j++){
????????????????????????a[i][j] = 0;
????????????????????????b[i][j] = 0;
????????????????}
????????}
??
????????for (int i = 0; i < n; i++){
????????????????for (int j = 0; j < m; j++){
????????????????????????cin >> a[i][j];
????????????????}
????????}
??
????????for (int i = 0; i < m; i++){
????????????????for (int j = 0; j < l; j++){
????????????????????????cin >> b[i][j];
????????????????}
????????}
??
????????for (int i = 0; i < n; i++){
????????????????for (int j = 0; j < l; j++){
????????????????????????c[i][j] = 0;
????????????????????????for (int k = 0; k < m; k++){
????????????????????????????????c[i][j] += a[i][k] * b[k][j];
????????????????????????}
????????????????????????if (j != 0) cout << " ";
??
????????????????????????cout << c[i][j];
????????????????}
????????????????cout << endl;
????????}
??
??
????????return 0;
}

Compiler output:
a.cc:3:1: error: expected unqualified-id before '?' token
    3 | ??
      | ^
Language: C++

 #include <iostream>
 using namespace std ;
 int main(){
 	int n , m , l , i , j , k ;
 	int a[100][100] , b[100][100] , c[100][100] ;
 	cin >> n >> m >> l ;
 	for( i=1 ; i<=n ; i++ ){
 		for( j=1 ; j<=m ; j++ ){
 			cin >> a[i][j] ;
 		}
 	}
 	for( i=1 ; i<=m ; i++ ){
 		for( j=1 ; j<=l ; j++ ){
 			cin >> b[i][j] ;
 		}
 	}
 	for( i=1 ; i<=n ; i++ ){
 		for( j=1 ; j<=l ; j++ ){
 			for( k=1 ; k<=m ; k++ ){
 				c[i][j]  += a[i][k] * b[k][j] ;
 			}
 			cout <<" "a<< c[i][j] ;
 		}
 		cout << endl ;
 	}
 }

Compiler output:
a.cc: In function 'int main()':
a.cc:22:32: error: unable to find string literal operator 'operator""a' with 'const char [2]', 'long unsigned int' arguments
   22 |                         cout <<" "a<< c[i][j] ;
      |                                ^~~~