Go: package main

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

//util
var sc = bufio.NewScanner(os.Stdin)

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 printList(list []int) {
	buf := bufio.NewWriter(os.Stdout)
	for _, v := range list {
		buf.Write([]byte(fmt.Sprintf(" %d", v)))
	}
	buf.Write([]byte("\n"))
	buf.Flush()
}

//solve
//単純な場合
func matrixChainMultiplication() {
	//行列が1つだけのとき
	for i := 1; i <= n; i++ {
		m[i][i] = 0
	}
	for l := 2; l <= n; l++ {
		for i := 1; i <= n-l+1; i++ {
			j := i + l - 1
			m[i][j] = 1 << 21
			//kまでで区切る
			for k := i; k <= j-1; k++ {
				m[i][j] = min(m[i][j], m[i][k]+m[k+1][j]+p[i-1]*p[k]*p[j])
			}
		}
	}
}

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

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

const MAX = 100

var n int
var p [MAX + 1]int

//m[i][j]: Mi * Mi+1 * ... * Mjを計算するときに必要なスカラー乗算の最小回数
var m [MAX + 1][MAX + 1]int

func main() {
	sc.Split(bufio.ScanWords)
	n = nextInt()
	for i := 1; i <= n; i++ {

		p[i-1] = nextInt() //行数
		p[i] = nextInt()   //列数
	}

	matrixChainMultiplication()
	fmt.Println(m[1][n])
}

C++: #include <stdio.h>
#include <algorithm>

using namespace std;


int main(){
	int n,minimum,tmp;
	scanf("%d",&n);
	int table[n][n];
	int data[n][2];

	for(int i=0;i<n;i++){
		for(int k=0;k<n;k++)table[i][k] = 0;
		scanf("%d %d",&data[i][0],&data[i][1]);
	}

	for(int i=n-2;i>=0;i--){
		for(int k=0;k<=i;k++){
			if(i==n-2){
				table[n-i-1][k] = data[k][0]*data[k][1]*data[k+1][1];
		}else{
				minimum = 2147483647;
				for(int p=0;p<=n-i-2;p++){
					tmp=(table[p][k]+table[n-i-p-2][k+p+1])+(data[k][0]*data[k+p][1]*data[k+n-i-1][1]);
					minimum = min(minimum,tmp);
				}
				table[n-i-1][k] = minimum;
			}
		}
	}

	printf("%d\n",table[n-1][0]);

    return 0;
}

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

static const int N = 100;

int main(){
  int n,p[N+1],m[N+1][N+1];
  cin >> n;
  for(int i = 1;i <= n;i++){
    cin >> p[i-1] >> p[i];
  }

  for(int i = 1; i <= n;i++)m[i][i] = 0;
  for(int l = 2; l <= n;l++){
    for(int i = 1;i <= n - l + 1;i++){
      int j = i + l - 1;
      m[i][j] = (1 << 21);
      for(int k = i;k <= j - 1;k++){
        m[i][j] = min(m[i][j], m[i][k] + m[k+1][j] + p[i-1] * p[k] * p[j]);
      }
    }
  }

  cout << m[1][n] << endl;

  return 0;
}

C++: #include <bits/stdc++.h>
using namespace std;
using ll = long long;

signed
main(){
		int N;
		cin >> N;
		vector<ll> a(N+1);
		for(int i=0;i<N;i++){
				cin >> a[i] >> a[i+1];
		}
	
		vector<vector<ll> > m(N+1, vector<ll>(N+1,INT_MAX));

		for(int i=0;i<=N;i++)
				m[i][i] = 0;
		for(int i=0;i<N;i++)
				m[i][i+1] = 0;


		for(int sa=2;sa<=N;sa++){
				for(int b=0;b<=N-sa;b++){
						int e = b + sa;
						for(int med=b;med<=e;med++){
								m[b][e] = min(m[b][e], m[b][med] + m[med][e] + a[b]*a[med]*a[e]);
						}
				}
		}
		cout << m[0][N] << endl;

}

C++: #include <iostream>
#include <vector>
using namespace std;
typedef long long ll;

ll m[101][101];
vector<ll> p;

int main() {

    int n;
    cin >> n;
    ll a, b;
    for (int i = 0; i < n; i++) {
        cin >> a >> b;
        if (i == 0) 
            p.push_back(a);
        p.push_back(b);
    }

    for (int i = 0; i < n; i++) 
        m[i][i] = 0;
    // l: length
    for (int l = 1; l < n; l++) {
        for (int i = 0; i < n - l; i++) {
            int j = i + l;
            m[i][j] = (1 << 21);
            for (int k = i; k < j; k++) {
                ll q = m[i][k] + m[k+1][j] + p[i] * p[k+1] * p[j+1];
                
                if( q < m[i][j] )
                    m[i][j] = q;
            }
        }
    }

    cout << m[0][n-1] << '\n';
}

C++: #include <stdio.h>
#include <stdlib.h>
#include <stdlib.h>
#include <math.h>
#define MAX 100
void min(int,int);
int p[MAX]={},m[MAX][MAX]={},i,j,k;

void min(int n1,int n2){
  if(n1>n2) n2=n1;
}
    
int main()
{
  int n,r,l;

  scanf("%d",&n);

  for(i=1;i<=n;i++){
    scanf("%d %d",&p[i-1],&p[i]);
  }

  for(i=1;i<=n;i++){
    m[i][i]=0;
  }

  for(l=2;l<=n;l++){
    for(i=1;i<=n-l+1;i++){
      j=i+l-1;
      m[i][j]=(1<<21);
      for(k=i;k<=j-1;k++){
	min(m[i][j],m[i][k]+m[k+1][j]+p[i-1]*p[k]*p[j]);
      }
    }
  }

  printf("%d\n",m[l][n]);

  return 0;
}

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

int n;
int r[101],c[101];
long long int dp[101][101];
int null = -1;
long long int ans;
long long int inf = 1<<24;
long long int dfs(int i,int j){
    long long int res=inf;
    if(dp[i][j] != null){
        return dp[i][j];
    }
    else if(i == j){
        res = 0;
    }
    else{
        for(int k=i;k<j;k++){
            res = min(dfs(i,k) + dfs(k+1,j) + r[i]*c[k]*c[j],res);
        }
    }

    dp[i][j] = res;
    //cout << i << " " << j << " " << dp[i][j] << endl;
    return res;
}

int main(){
    cin >> n;
    for(int i=0;i<n;i++){
        cin >> r[i] >> c[i];
    }
    for(int i=0;i<=n;i++){
        for(int j=0;j<=n;j++){
            dp[i][j] = null;
        }
    }
    ans = dfs(0,n-1);
    cout << ans << endl;
    return 0;

}

C++: #include <bits/stdc++.h>
using namespace std;

const int INF = 1e9;

int N;
vector<int> R, C;
vector<vector<int> > dp;

int dfs(int l, int r) {
  if ( r == l ) return 0;
  if ( dp[l][r] ) return dp[l][r];

  int ret = INF;
  for ( int i = l; i < r; i++ ) {
    ret = min(ret, dfs(l, i)+dfs(i+1, r)+R[l]*C[i]*C[r]);
  }
  
  return dp[l][r] = ret;
}

int main() {  
  cin >> N;

  R = vector<int>(N);
  C = vector<int>(N);
  for ( int i = 0; i < N; i++ ) {
    cin >> R[i] >> C[i];
  }

  dp = vector<vector<int> >(N, vector<int>(N, 0));

  cout << dfs(0, N-1) << endl;
  
  return 0;
}

C++: #include <bits/stdc++.h>
using namespace std;
#define FOR(i,a,b) for(int i=(a);i<(b);++i)
#define rep(i,n)   FOR(i,0,n)
#define pb emplace_back
typedef long long ll;
typedef pair<int,int> pint;

int dp[102][102],p[102];
const int INF=1000100010;
int main(){
    int n,l,r;
    cin>>n;
    rep(i,n){
        cin>>l>>r;
        if(i!=n-1) p[i]=l;
        else p[i]=l,p[i+1]=r;
    }
    FOR(i,1,n+1)FOR(j,1,n+1){
        if(i!=j)dp[i][j]=INF;
        else dp[i][j]=0;
    }
    FOR(i,1,n+1)FOR(l,1,n-i+1)FOR(r,l+1,i+l+1){
        dp[l][i+l]=min(dp[l][i+l],dp[l][r-1]+dp[r][i+l]+p[l-1]*p[r-1]*p[l+i]);
    }
    cout<<dp[1][n]<<endl;
    return 0;
}

C++: #include <iostream>
#include <string>
#include <algorithm>
#include <stdio.h>
#include <memory.h>
using namespace std;

struct matrix {
	int row;
	int col;
};
int main()
{
	int N;
	scanf("%d", &N);
	matrix vec[100];
	memset(vec, 0, sizeof(vec));
	for (int i = 0; i < N; ++i) {
		scanf("%d %d", &vec[i].row, &vec[i].col);
		//cin >> vec[i].row >> vec[i].col;
	}
	//vector<vector<int>> dp(N, vector<int>(N));
	int dp[100][100];
	memset(dp, 0, sizeof(dp));
	for (int len = 1; len < N; ++len) {
		for (int i = 0; i + len < N; ++i) {
			int j = i + len;
			dp[i][j] = 2147483647;
			for (int k = i; k < i + len; ++k) {
				dp[i][j] = min(dp[i][k] + dp[k + 1][j] + vec[i].row * vec[k].col * vec[j].col, dp[i][j]);
			}
		}
	}
	printf("%d\n", dp[0][N - 1]);
	//cout << dp[0][N - 1] <<endl;
	return 0;
}