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<iostream>
#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
#define rep(i,n) for(int i=0;i<n;i++)

/* 大文字を小文字に変換 */
char tolower(char c) {return (c + 0x20);}
/* 小文字を大文字に変換 */
char toupr(char c) {return (c - 0x20);}

// if('A'<=s[i] && s[i]<='Z') s[i] += 'a'-'A';

/*
string s = "abcdefg"
s.substr(4) "efg"
s.substr(0,3) "abc"
s.substr(2,4) "cdef"
*/

const int INFTY = pow(10, 8);

int main()
{
    int n; cin >> n;
    int p[n+1];
    int m[n+1][n+1];
    rep(i,n){
        m[i][i] = 0;
        int p1, p2; cin >> p1 >> p2;
        p[i] = p1;
        if(i == n-1){
            m[i+1][i+1] = 0;
            p[i+1] = p2;
        }
    }

    for(int l=2; l<=n; l++){
        for(int i=1; i<=n-l+1; i++){
            int j = i+l-1;
            m[i][j] = INFTY;
            for(int k=i; k<j; 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;
}

C++: #include <stdio.h>
#include <iostream>
#define INFTY 200000000
using namespace std;

int main(void){
    int n;
    int m[100][100];
    int p[101];

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

    for(int i = 0; i < n; i++){
        for(int j = 0; j < n; j++){
            if(i > j)
                m[i][j] = INFTY;
            if(i == j) 
                m[i][j] = 0;
        }
    }
    
    for(int i = 0; i <= n - 2; i++){
        m[i][i + 1] = p[i] * p[i + 1] * p[i + 2];
    }

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

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

}

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

using namespace std;
static const int N = 100;


void solve(vector<int> &data)
{
	vector<vector<int>> dp(N + 1, vector<int>(N + 1, 0));

	int nums = data.size() - 1;
	for (int len = 2; len <= nums; ++len)
	{
		for (int l = 1; l <= nums - len + 1; ++l)
		{
			int r = l + len - 1;
			dp[l][r] = INT_MAX;
			for (int m = l; m <= r - 1; ++m)
			{
				cout << len << " " << l << " " << r << endl;
				dp[l][r] = min(dp[l][r], dp[l][m] + dp[m+1][r] + data[l - 1] * data[m] * data[r]);
			}
		}
	}

	cout << dp[1][nums] << endl;
}

int main()
{
	int num; cin >> num;
	vector<int> data(num + 1);
	for (int i = 1; i <= num; ++i)
		cin >> data[i-1] >> data[i];

	solve(data);
}

C++: #include<stdio.h>
#include<stdlib.h>
#include<limits.h>
#define N 101

int main(){
  int a[N],b[N][N];
  int i,n,k,j,l=0,tmp=0;

  scanf("%d",&n);

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

  for(i=1;i<=n;i++){
    b[i][i]=0;
  }
  for(j=2;j<=n;j++){
    for(i=1;i<=n-j+1;i++){
      k=i+j-1;
      b[i][k]=INT_MAX;
      for(l=i;l<=k-1;l++){
        tmp=b[i][l]+b[l+1][k]+a[i-1]*a[l]*a[k];

    if(b[i][k]>tmp){
      b[i][k]=tmp;
    }else{
      b[i][k]=b[i][k];
    }
      }
    }
  }
  printf("%d\n",b[1][n]);
  return 0;
}

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

#define MAX (1 << 21)
const int N = 1000;

int main() {
    int n;
    int m[N + 1][N + 1];
    int p[N + 1];
    for (int i = 1; i <= N; i++)
        m[i][i] = 0;
    cin >> n;
    for (int i = 0; i < n; i++) {
        cin >> p[i] >> p[i + 1];
    }
    for (int i = 2; i <= n; i++) {
        for (int j = 1; j <= n - i + 1; j++) {
            int k = j + i - 1;
            m[j][k] = MAX;
            for (int l = j; l < k; l++) {
                m[j][k] = min(m[j][k], m[j][l] + m[l + 1][k] + p[j - 1] * p[l] * p[k]);
            }
        }
    }
    cout << m[1][n] << endl;
    return 0;
}

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

signed main(){
    // cout << fixed << setprecision(10) << flush;

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

    // 最後の行列をどうやって掛けるか
    // (i-1)個 * 1個, (i-2) * (1 * 1), (i-3) * (2 * 1), ..., 1 * ((i-2) * 1)
    // のうちから最小を求め、ストックする
    // 0 <= i <= n
    // つまり、左から i 番目から j 番目までかけたときの最小の乗算の数、をストックしておく必要がある
    // dp[i][i] = 0
    // dp[i][j] = min_{i<=i_j<j} ((i ~ i_j までまとめたときの最小値) + r[i]*c[i_j]*c[j] + (i_j+1 ~ j-1 までまとめたときの最小値 + r[i_j+1]*c[j-1]*r[j]))
    // dp[i][j] = min_{i<=i_j<j} (dp[i][i_j] + r[i]*r[i_j]*c[j] + (dp[i_j+1][j-1] + r[i_j]*r[j]*c[j]))
    int INF = 1<<30;
    INF = INF<<30;
    vector<vector<int>> dp(n, vector<int>(n, INF));
    for(int i=0; i<n; i++){
        for(int j=0; j<=i; j++){
            dp[i][j] = 0;
        }
    }
    for(int i=n-1; i>=0; i--){
        for(int j=i+1; j<n; j++){
            dp[i][j] = dp[i][j-1] + r[i]*r[j]*c[j];
            for(int i_j=i; i_j<j; i_j++){
                dp[i][j] = min(dp[i][j], dp[i][i_j] + r[i]*r[i_j+1]*c[j] + (dp[i_j+1][j-1] + r[i_j+1]*r[j]*c[j]));
            }
        }
    }
    cout << dp[0][n-1] << endl;
    return 0;
}

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

int main(){
	int n;
	std::vector< int > r, c;
	std::vector< std::vector< int > > dp;
	
	std::cin >> n;
	r.resize(n);
	c.resize(n);
	dp.resize(n);
	
	for(int i=0; i<n; ++i){
		std::cin  >> r[i] >> c[i];
		dp[i].resize(n);
		dp[i][i] = 0;
	}
	
	for(int m=1; m<n; ++m){
		for(int i=0; i<n; ++i){
			int j = m + i;
			if(j>=n)break;
			
			int min = -1;
			for(int k=i; k<j; ++k){
				int t = dp[i][k] + dp[k+1][j] + r[i] * c[k] * c[j];
				
				if(min == -1 || min > t){
					min = t;
				}
			}
			dp[i][j] = min;
		}
	}
	
	std::cout << dp[0][n-1] << std::endl;
	
	return 0;
}