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 <bits/stdc++.h>
using namespace std;
//using ll = long long;
#define MAX 100000000000000;

/*
int MCM(int i, int j, int p[]) {
  int min = MAX;
  if (i == j) return 0;
  if (i < j) {
    int temp;
    for (int k = i; k < j; k++) {
      temp = MCM(i, k, p)+MCM(k+1, j, p)+p[i-1]*p[k]*p[j];
      if (min > temp) min = temp;
    }
  }
  return min;
}
*/

int main(void) {
  int n; cin >> n;
  int r[n]; int c[n];
  for (int i = 0; i < n; i++) {
    cin >> r[i] >> c[i];
  }

  long long m[n+1][n+1]; int p[n+1];
  for (int i = 0; i < n; i++) p[i] = r[i]; p[n] = c[n-1];
  for (int i = 1; i <= n; i++) m[i][i] = 0;
  //int ans = MCM(1, n, p);
  //cout << ans << endl;  
  for (int k = 1; k < n; k++) { //kはm[i][j]におけるj-iの値
    for (int i = 1; i+k <= n; i++) { //iはm[i][j]におけるi
    long long temp; m[i][i+k] = MAX; //tempmin_はm[i][i+k]の値
      for (int l = i; l < i+k; l++) { //lはm[i][i+k]を分割する地点
        temp = m[i][l]+m[l+1][i+k]+p[i-1]*p[l]*p[i+k];
        if (m[i][i+k] > temp) m[i][i+k] = temp;
      }
    }
  }
  cout << m[1][n] << endl;
}

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

const int N=100;

int main(){
	int n;
	long m[N+1][N+1], p[N+1];
	
	scanf(" %d", &n);
	for(int i=1; i<=n; ++i)
		scanf(" %ld %ld", &p[i-1], &p[i]);
		
	for(int i=0; i<=n; ++i) printf("p[%d]=%ld\n", i, p[i]);
		
	for(int i=1; i<=n; ++i) m[i][i]=0;
	
	for(int s=2; s<=n; ++s){ //s??????????????????
		for(int i=1; i+s-1<=n; ++i){ //?§????i
			int j=i+s-1; //??????j
			m[i][j]=100000000; //????????§???????????§?????????
			for(int k=i; k<=j-1; ++k){ //?????????k
				m[i][j]=min(m[i][j], m[i][k]+m[k+1][j]+p[i-1]*p[k]*p[j]);
				//printf("go %d %d %d\n",i, j, k);
			}
		}
	}
	
	printf("%ld\n", m[1][n]);
}

C++: #include<bits/stdc++.h>
#define INF 1e9

using namespace std;

int main()
{
  int n;
  int a[105];
  
  cin >> n;

  for(int i=0;i < n;i++){
    cin >> a[i] >> a[i+1];
  }
  //dp[i][j] := iからj番目の行列積に必要なスカラー積の最小値
  int dp[105][105] = {};

  //init
  for(int i=0;i < n;i++){
    for(int j=0;j < n;j++){
      if(i == j) dp[i][j] = 0;//iからiまでは当然 0回
      else dp[i][j] = INF;
    }
  }
  
  for(int m = 0; m < n ;m++){
    for(int i = 0; m+i < n ;i++){
      int j = m+i;
      for(int k = i; k < j ;k++){
	dp[i][j] = min(dp[i][j], dp[i][k] + dp[k+1][j] + a[i]*a[k+1]*a[j+1]);
      }
    }
  }
  cout << dp[0][n-1] << endl;
  return 0;
}

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

int main() {
	int n, p[101], m[101][101];
	std::cin >> n;
	for (int i = 1; i <= n; i++) {
		std::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] = std::min(m[i][j], m[i][k] + m[k + 1][j] + p[i - 1] * p[k] * p[j]);
			}
		}
	}
	std::cout << m[1][n] << std::endl;
	return 0;
}

C++: #include "bits/stdc++.h"
#define rep(i,n) for(int i=0;i<n;i++)
using namespace std;

using ll = long long;

int main() {
    // dp[i][j] i番目からj番目までの最小値
    int n;
    cin >> n;
    vector<int> r(n), c(n);
    rep(i, n) cin >> r[i] >> c[i];
    vector<vector<int>> dp(n, vector<int>(n, 1e9));
    rep(i, n) dp[i][i] = 0;
    for (int w = 1; w < n; w++) {
        //cout << "w=" << w << " ";
        for (int a = 0; a + w < n; a++) {
            //cout << "a=" << a << " ";
            int d = 1e9;
            for (int b = a; b <= a + w - 1; b++) {
                //cout << "b=" << b << " ";
                d = min(d, dp[a][b] + dp[b + 1][a + w] + r[a] * c[b] * c[a + w]);
            }
            dp[a][a + w] = d;
            //cout << "dp[" << a << "][" << a + w << "]=" << dp[a][a + w] << "\n";
        }
    }
    cout << dp[0][n - 1] << "\n";
}