Go: package main

import (
	"bufio"
	"fmt"
	"os"
	"strconv"
)

//Util
func nextStr() string {
	sc.Scan()
	return sc.Text()
}

func nextInt() int {
	sc.Scan()
	i, e := strconv.Atoi(sc.Text())
	if e != nil {
		panic(e)
	}
	return i
}

func maxInt(a, b int) int {
	if a > b {
		return a
	} else {
		return b
	}
}

func minInt(a, b int) int {
	if a > b {
		return b
	} else {
		return a
	}
}

func absInt(a int) int {
	if a >= 0 {
		return a
	} else {
		return -a
	}
}

func absFloat64(a float64) float64 {
	if a >= 0 {
		return a
	} else {
		return -a
	}
}

func minFloat64(a, b float64) float64 {
	if a > b {
		return b
	} else {
		return a
	}
}

func str2Int(s string) int {
	n, _ := strconv.Atoi(s)
	return n
}

//Main
var sc = bufio.NewScanner(os.Stdin)
var q int
var X, Y string

func lcs(X, Y string) int {
	lenX := len(X)
	lenY := len(Y)
	dp := make([][]int, lenX+1)
	for i := 0; i < lenX+1; i++ {
		dp[i] = make([]int, lenY+1)
	}

	res := 0
	for i := 1; i < lenX+1; i++ {
		for j := 1; j < lenY+1; j++ {
			if X[i-1] == Y[j-1] {
				dp[i][j] = dp[i-1][j-1] + 1
			} else {
				dp[i][j] = maxInt(dp[i-1][j], dp[i][j-1])
			}
			//fmt.Println(dp)
			res = maxInt(res, dp[i][j])
		}

	}
	return res
}

func main() {
	sc.Split(bufio.ScanWords)
	q = nextInt()

	for i := 0; i < q; i++ {
		X = nextStr()
		Y = nextStr()

		fmt.Println(lcs(X, Y))
	}
}

C++: #include <iostream>
#include <string>
#include <algorithm>
using namespace std;

 const int N = 1000;

int lcs(string X,string Y){
    int C[N+1][N+1];
    int m = X.size();
    int n = Y.size();
    int maxl = 0;
    X = ' ' + X;
    Y = ' ' + Y;
    for (int i = 1; i <= m ; ++i) {
        C[i][0] = 0;
    }
    for (int j = 1; j <= n ; ++j) {
        C[0][j] = 0;
    }

    for (int i = 1; i <= m ; ++i) {
        for (int j = 1; j <= n ; ++j) {
         if (X[i] == Y[j]){
             C[i][j] = C[i-1][j-1] + 1;
         }else{
             C[i][j] = max(C[i-1][j],C[i][j-1]);
         }
            maxl = max(maxl,C[i][j]);
        }
    }
    return maxl;
}


int main(){
    string s1,s2;
    int n;
    cin >> n;
    for (int i = 0; i < n ; ++i) {
        cin >> s1 >> s2;
        cout << lcs(s1,s2) << endl;
    }
    return 0;
}

C++: #include<stdio.h>
#include<string.h>
   
int LCS(char *X, char *Y){
  int i,j,m,n,c[1001][1001];
  m = strlen(X);
  n = strlen(Y);
     
  for(i=0; i<m; i++){
    c[i][0] = 0;
  }
  for(j=0; j<n; j++){
    c[0][j] = 0;
  }
   
  for(i=1;i<m+1;i++){
    for(j=1;j<n+1;j++){
      if (X[i-1]==Y[j-1]) c[i][j]=c[i-1][j-1]+1;
      else if (c[i-1][j]>=c[i][j-1]) c[i][j]=c[i-1][j];
      else c[i][j]=c[i][j-1];
    }
  }
  return c[i-1][j-1];
}
   
int main(){
  int i, q;
  char X[1001], Y[1001];
     
  scanf("%d", &q);
  for(i=0; i<q; i++){
    scanf("%s", X);
    scanf("%s", Y);
    printf("%d\n", LCS(X, Y));
   
  }
  return 0;
}

C++: #include<iostream>
#include<cstdio>
#include<cstring>
#define _A_ true
using namespace std;

int main(){
  int n,AC=0;
  int dp[1010][1010];
  char A[1500],B[1500];
  scanf("%d",&n);
  while(_A_){
    if(AC == n)break;
    scanf("%s",A);
    scanf("%s",B);
    for(int i=0;i<1010;i++)for(int j=0;j<1010;j++)dp[i][j]=0;

    for(int i=0;i<strlen(A);i++){
      for(int j=0;j<strlen(B);j++){
	if(A[i] == B[j]){
	  dp[i+1][j+1]=dp[i][j]+1;
	}
	else{
	  if(dp[i+1][j] > dp[i][j+1]){
	    dp[i+1][j+1]=dp[i+1][j];
	  }
	  else {
	    dp[i+1][j+1] = dp[i][j+1];
	  }
	}
      }
    }
    printf("%d\n",dp[strlen(A)][strlen(B)]);
    AC++;
  }
  return 0;
}

C++: #include<iostream>
#include<algorithm>
#include<string>

using namespace std;

int main(){
  string X,Y;
  int n;
  cin>>n;
  int ans[n];
  int l=0;
 int point;

  for(int i=0;i<n;i++){
    ans[i]=0;
  }

  for(int m=0;m<n;m++){
  cin>>X>>Y;
 int N[X.size()+1][Y.size()+1];

  for(int i=0;i<=X.size();i++){
    for(int j=0;j<=Y.size();j++){

      N[i][j]=0;
}
  }

 
 

  for(int i=1;i<=X.size();i++){
    for(int j=1;j<=Y.size();j++){
      if(X[i-1]==Y[j-1]){
	point=1;
	
      }else{
	point=0;
      }
       N[i][j]=max({N[i-1][j],N[i][j-1],N[i-1][j-1]+point});
       point=0;
}
   
  }
  // ans[l]=N[X.size()][Y.size()];

  cout<<N[X.size()][Y.size()]<<endl;
  // l++;

  }
  //  cout<<ans[0]<<endl;
  // cout<<ans[1]<<endl;
  //cout<<ans[2]<<endl;

 return 0;
}

C++: #include <map>
#include <set>
#include <list>
#include <cmath>
#include <queue>
#include <stack>
#include <cstdio>
#include <string>
#include <vector>
#include <complex>
#include <cstdlib>
#include <cstring>
#include <numeric>
#include <sstream>
#include <iostream>
#include <algorithm>
#include <functional>

#define mp       make_pair
#define pb       push_back
#define all(x)   (x).begin(),(x).end()
#define rep(i,n) for(int i=0;i<(n);i++)
#define repi(i,a,b) for(int i = (a); i < (b); i++)

using namespace std;

typedef    long long          ll;
typedef    unsigned long long ull;
typedef    vector<bool>       vb;
typedef    vector<int>        vi;
typedef    vector<vb>         vvb;
typedef    vector<vi>         vvi;
typedef    pair<int,int>      pii;

const int INF=1<<29;
const double EPS=1e-9;

const int dx[]={1,0,-1,0},dy[]={0,-1,0,1};
int dp[1050][1050];
int main(){
	int n;
	cin>>n;
	while(n--){
		memset(dp, 0, sizeof(dp));
		string str1,str2;
		cin>>str1>>str2;
		//int l =min(str1.length(),str2.length());
		for(int i =0;i <str1.length();i++){
			for(int j =0;j <str2.length();j++){
				if(str1[i]==str2[j]){
					dp[i+1][j+1]=dp[i][j]+1;
				}else{
					dp[i+1][j+1]=max(dp[i][j+1],dp[i+1][j]);
				}
			}
		}
		cout <<dp[str1.length()][str2.length()]<<endl;
	}
	return 0;
}

C++: #include <bits/stdc++.h>
using namespace std;
typedef long long LL;
typedef unsigned long long ULL;
#define BIG_NUM 2000000000
#define MOD 1000000007
#define EPS 0.000000001
int dp[1010][1010];
int main(){
  int q;
  cin >> q;
  for(int i=0;i<q;i++){
    for(int j=0;j<1010;j++){
      fill(dp[j],dp[j]+1010,0);
    }
    string a,b;
    cin >> a >> b;
    for(int j=0;j<a.size();j++){
      for(int k=0;k<b.size();k++){
        if(a[j] == b[k]){
          dp[j+1][k+1] = dp[j][k] + 1;
        }else{
          dp[j+1][k+1] = max(dp[j+1][k] ,dp[j][k+1]);
        }
      }
    }
    cout << dp[a.size()][b.size()] << endl;
  }
  return 0;
}

C++: #include<iostream>
#include<algorithm>
#include<string>

using namespace std;

int main () {

    int N, m, n, i, j, k, c[1001][1001];
    string x, y;

    cin >> N;

    for (k = 0; k < n; k++) {
        cin >> x >> y;
        m = x.size ();
        n = y.size ();

        for (i = 1; i <= m; i++) {
            for (j = 1; j <= n; j++) {

                if (x[i - 1] == y[j - 1]) {
                    c[i][j] = c[i - 1][j - 1] + 1;
                } else {
                    c[i][j] = max (c[i - 1][j], c[i][j - 1]);
                }

            }
        }

    cout << c[m][n] << endl;

    }

}

C++: #include<stdio.h>
#include<string>
#include<algorithm>
using namespase std;
static const int N = 1000;

int lcs(string X, string Y){
  int c[N + 1][N + 1];
  int m = X.size();
  int n = Y.size();
  int maxl = 0;
  X = ' ' + X;
  Y = ' ' + Y;
  for( int i = 1; i <= m; i++) c[i][0] = 0;
  for( int j = 1; j <= n; j++) c[0][j] = 0;

  for( int i = 1; i <= m; i++){
    for( int j = 1; j <= n; j++){
      if( X[i] == Y[j] ){
        c[i][j] = c[i -1][j - 1] + 1;
       } else {
       c[i][j] = max(c[i -1][j], c[i][j = 1]);
       }
       maxl = max(maxl, c[i][j];
     }
  }

  return maxl;
}


int main(){
  string s1, s2;
  int n; cin >> n;
  for( int i = 0; i < n; i++){
    cin >> s1 >> s2;
    cout << lcs(s1, s2) << endl;
  }
  
  return 0;
}