Go: package main

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

type Matrix struct {
	r int // num of row
	c int // num of column
}

type Range struct {
	start int // index, inclusive
	end   int // index, inclusive
}

func (r Range) length() int {
	return r.end - r.start + 1
}

func calcMultiplication(x, y Matrix) (Matrix, int) {
	if x.c != y.r {
		panic("cannnot calculate")
	}
	return Matrix{x.r, y.c}, x.r * y.c * x.c
}

func calcMinMatrixChainMultiplication(matrices []Matrix, r Range, memo map[Range]int) (Matrix, int) {
	if v, ok := memo[r]; ok {
		return Matrix{matrices[r.start].r, matrices[r.end].c}, v
	}
	if r.length() == 0 {
		panic("must not be empty")
	} else if r.length() == 1 {
		return matrices[r.start], 0
	}

	var minCount int = math.MaxInt32

	for i := 0; i < r.length()-1; i++ {
		formerRange := Range{r.start, r.start + i}
		latterRange := Range{r.start + i + 1, r.end}
		matF, countF := calcMinMatrixChainMultiplication(matrices, formerRange, memo)
		matL, countL := calcMinMatrixChainMultiplication(matrices, latterRange, memo)
		_, countFL := calcMultiplication(matF, matL)
		count := countF + countL + countFL
		if count < minCount {
			minCount = count
		}
	}
	memo[r] = minCount
	return Matrix{matrices[r.start].r, matrices[r.end].c}, minCount
}

func main() {
	sc := bufio.NewScanner(os.Stdin)
	sc.Split(bufio.ScanWords)
	n, _ := nextInt(sc)
	matrices := make([]Matrix, n)
	for i := 0; i < n; i++ {
		r, _ := nextInt(sc)
		c, _ := nextInt(sc)
		matrices[i] = Matrix{r, c}
	}
	memo := make(map[Range]int)
	_, resultCount := calcMinMatrixChainMultiplication(matrices, Range{0, len(matrices) - 1}, memo)
	fmt.Println(resultCount)
}

func nextInt(sc *bufio.Scanner) (int, error) {
	sc.Scan()
	return strconv.Atoi(sc.Text())
}

C++: #include<cstdio>
#include<cstring>

int r[105];
int c[105];
int cache[105][105];

int f(int a, int b){
	if(a==b)
		return 0;
	if(cache[a][b] == -1)
	{
		cache[a][b] = 1000000000; 
		for(int i = a; i<b; i++){
			int res = f(a,i) +f(i+1, b) +r[a]*c[i]*c[b];
			if(res<cache[a][b])
				cache[a][b] = res;
		}
	}
	return cache[a][b];
	
}

int  main(){
	int n;
	scanf("%d",&n);
	for(int i = 0; i<n; i++){
		scanf("%d %d",&r[i], &c[i]);	
	}
	memset(cache, -1, sizeof(cache));
	printf("%d\n",f(0,n-1));
}

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


static const int N = 100;

int m[N+1][N+1];
int main()
{
    int n,p[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;
    int i;
    for(int l=2;l<=n;l++)
    {
        for(int i=1;i<=n-l+1;i++)
        {
            int j=i+l-1;
            m[i][j]=(9999999);
            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 << "l i j k m[i][j]:" <<l<<" " << i << " " << j << " "<<k<<" "<<m[i][j]<<endl;
            }
        }
    }
    cout <<m[1][n] << endl;

    return 0;
}

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

struct Matrix{
  int x, y;
};

int dp[111][111];
vector<Matrix> v;
Matrix matrix[111][111];

int main(){

  int n, r, c;

  cin >> n;

  for(int i = 0; i < n; i++){
    cin >> r >> c;
    v.push_back((Matrix){r,c});
  }

 
  for(int i = 0; i < n; i++) dp[i][i] = 0;
  for(int i = 1; i < n; i++){
    for(int j = 0; j < n - i; j++){
      int s = j + i;
      dp[j][s] = INT_MAX;
      for(int l = j; l < s; l++){
	dp[j][s] = min(dp[j][s],dp[j][l] + dp[l+1][s] + v[j].x * v[s].y * v[l].y);
      }
    }
  }
  cout << dp[0][n-1] << endl;
 }

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>
#define _GLIBCXX_DEBUG
#define rep(i, n) for (int i = 0; i < (n); ++i)
#define rrep(i, n) for (int i = 1; i < (n+1); ++i)
using namespace std;
using ll = long long;
const int INF = +100100100;
// typedef pair<int,int> P;

vector<int>P;

int dp(int n){
    vector<vector<int>> D(n,vector<int>(n));
    rep(j,n){
        for(int i = j;i>=0;--i){
            if(i==j)D[i][j]=0;
            else{
                int mini = INF;
                for(int k = i;k<j;++k){
                    int rel = D[i][k]+D[k+1][j]+P[i]*P[k+1]*P[j+1];
                    mini = min(mini,rel);
                }
                D[i][j]=mini;
            }
        }
    }
    return D[0][n-1];
}

int main(){
    int n;
    cin>>n;
    rep(i,n){
        int x,y;cin >> x>>y;
        if(i==0){
            P.push_back(x);
            P.push_back(y);
        }
        else{
            P.push_back(y);
        }
    }
    cout << dp(n) << endl;
    return 0;
}

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

const int INF = INT_MAX/3;
typedef vector<int> vi;
typedef pair<int,int> pii;

int main(){
    int n;cin>>n;
    vector<pii> p(n+1);
    for(int i=0;i<n;i++) cin>>p[i].first>>p[i].second;

    vector<vi> mat(n+1,vi(n+1,INF));    //mat[i][j] : Mi*...*Mj???????°??????°
    for(int i=0;i<n;i++) mat[i][i] = 0;

    for(int sz=2;sz<=n;sz++){
        /*
         * mat[i][j] = min( mat[i][k]+mat[k+1][j]+Mi.first*Mk+1.first*Mk+1.second )
         */
      //  cout << "size = " << sz << endl;
        for(int i=0;i<=n-sz;i++){

            int j = i + sz - 1;

       //     cout << i << " : " << j << endl;

            for(int k=i;k<=j-1;k++){
        //        cout << i << ":" << j << ":" << mat[i][k] << ":" << mat[k+1][j] << endl;
                int tmp = mat[i][k] + mat[k+1][j] + p[i].first * p[k+1].first * p[j].second;
                //cout << tmp << endl;
                mat[i][j] = min(mat[i][j] , mat[i][k] + mat[k+1][j] + p[i].first * p[k+1].first * p[j].second);
            }
        }
    }

    /*
    for(int i=0;i<n;i++){
        for(int j=0;j<n;j++){
            cout << mat[i][j] << "\t";
        }
        cout << endl;
    }
    */

    cout << mat[0][n-1] << endl;
}

C++: #include <bits/stdc++.h>
using namespace std;
#define rep(i,s,n) for(int i = (s); i < (n); i++)

int main() {
  cin.tie(0);
  ios::sync_with_stdio(false);
  cout << fixed << setprecision(18);
  
  int n;
  cin >> n;
  int dp[n+1][n+1];
  rep(i, 1, n+1) dp[i][i] = 0;
  int p[n+1];
  rep(i, 0, n) cin >> p[i] >> p[i+1];
  
  rep(l, 2, n+1) {
    rep(i, 1, n-l+2) {
      int j = i+l-1;
      dp[i][j] = 1000000007;
      rep(k, i, j) {
        dp[i][j] = min(dp[i][j], dp[i][k] + dp[k+1][j] + p[i-1]*p[k]*p[j]);
      }
    }
  }
  
  cout << dp[1][n] << "\n";
}

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;
}