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;

typedef pair<int, int> pii;

int main(int argc, char *argv[]){
  int n;
  cin >> n;
  pii mat[n];
  int dp[n][n];
  int p[n + 1];

  //????????????
  for (int i = 0; i < n; i++) {
    cin >> mat[i].first >> mat[i].second;
  }
  for (int i = 0; i < n; i++) {
    p[i] = mat[i].first;
  }
  p[n] = mat[n - 1].second;
  for (int i = 0; i < n; i++) {
    for (int j = i; j < n; j++) {
      if(i != j)dp[i][j] = 1e9;
      else dp[i][j] = 0;
    }
  }
  //???????????§?????????
  //????????????DP
  for (int l = 2; l <= n; l++) {
    for (int i = 0; i <= n - l; i++) {
      int j = i + l - 1;
      for (int k = i; k < j; k++) {
        dp[i][j] = min(dp[i][j], dp[i][k] + dp[k + 1][j] +
                       p[i]*p[k + 1]*p[j + 1]);
      }
    }
  }
  std::cout << dp[0][n - 1] << std::endl;
            
  return 0;
}

C++: #include <iostream>
#include <vector>
int INF = 1e9;
int main(){
    int n;
    std::cin >> n;
    std::vector<int> g(n), re(n);
    for(int i = 0; i < n; i++) std::cin >> g[i] >> re[i];
    int dp[n + 1][n + 1];
    for(int i = 0; i < n + 1; i++){
        for(int j = 0; j < n + 1; j++) dp[i][j] = INF;
        if(i < n) dp[i][i + 1] = 0;
        dp[i][i] = 0;
    }
    for(int w = 1; w < n + 1; w++){
        for(int l = 0; l < n; l++){
            int r = l + w;
            if(r > n) break;
            if(r - l == 2) dp[l][r] = g[l]*re[l + 1]*g[r - 1];
            for(int mid = l + 1; mid < r; mid++){
                dp[l][r] = std::min(dp[l][mid] + dp[mid][r] + g[l]*re[r- 1]*re[mid - 1], dp[l][r]);
            }
        }
    }
    std::cout << dp[0][n] << std::endl;
}

C++: #include<iostream>
#include<algorithm>
#define N 100
using namespace std;

int main() {
  int n, p[N + 1], m[N + 1][N + 1], i, j, k, l;
  cin >> n;
  for(i = 1; i <= n; i++) {
    cin>>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++) {
        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 <iostream>
#include <cstdio>
#include <climits>
#include <cmath>
#include <algorithm>
#include <utility>
#include <vector>
#include <string>

#define MAX 200000
#define INFTY 1<<30

using namespace std;

static const int N = 1000;

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++)//???????????° 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 <stdio.h>
#include <limits.h>
#include <math.h>
#define INF INT_MAX

int n,p[101],m[101][101];

void matrixChainOrder(){
  int i,j,k,l,q;
  for(i=0;i<n;i++)m[i][i]=0;
  for(l=1;l<n;l++)
    for(i=0;i<n-l;i++){
      j=i+l;
      m[i][j]=INF;
      for(k=i;k<j;k++){
	q=m[i][k]+m[k+1][j]+p[i]*p[k+1]*p[j+1];
	m[i][j]=fmin(m[i][j],q);
      }
    }
}

int main(){
  int i;
  scanf("%d",&n);
  for(i=0;i<2*n;i++)scanf("%d",&p[i]);
  matrixChainOrder();
  printf("%d\n",m[0][n-1]);
  return 0;
}

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

template<typename T, typename U> void dmin(T &x, U y) { if(x > y) x = y; }

const int MAX_N = 100;
const int INF = 1001001001;

int main() {
  int n, r, c;
  int rc[MAX_N][2];
  cin >> n;
  for (int i=0; i<n; i++) {
    cin >> r >> c;
    rc[i][0] = r; rc[i][1] = c;
  }

  int dp[MAX_N][MAX_N];
  for (int i=0; i<n; i++) {
    for (int j=0; j<n; j++) {
      dp[i][j] = INF;
    }
    dp[i][i] = 0;
  }

  for (int l=2; l<=n; l++) {
    for (int i=0; i+l-1<n; i++) {
      for (int j=1; j<l; j++) {
        dmin(dp[i][i+l-1], dp[i][i+j-1] + rc[i][0]*rc[i+j-1][1]*rc[i+l-1][1] + dp[i+j][i+l-1]);
      }
    }
  }

  cout << dp[0][n-1] << endl;
  return 0;
}

C++: #include<bits/stdc++.h>
#define INF (1e9)
#define N 105
using namespace std;
int n,r[N],c[N],dp[N][N];

void matrixChainOrder(){
  for(int l=2;l<=n;l++){
    for(int i=0;i<=n-l;i++){
      int j=i+l-1;
      dp[i][j]=INF;
      for(int k=i;k<j;k++)
	dp[i][j]=min(dp[i][j],dp[i][k]+dp[k+1][j]+r[i]*c[k]*c[j]);
    }
  }
}

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

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

using namespace std;

int main() {
	int n;
	cin >> n;
	int m[101];
	int M[101][101];
	for (int i = 1; i <= n; i++) {
		cin >> m[i-1] >> m[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] = 100000000000000000;
			for (int k = i; k < j; k++) {
				M[i][j] = min(M[i][j], M[i][k] + M[k + 1][j] + m[i - 1] * m[k] * m[j]);
			}
		}
	}
	cout << M[1][n] << endl;
	return 0;
}

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

int main()
{
  int n;
  std::cin >> n;
  std::vector<std::pair<int, int>> data;
  for (int i = 0; i < n; i++){
    int l , r;
    std::cin>> l >> r;
    data.push_back(std::make_pair(l, r));
  }

  std::vector<std::vector<int>> dp(n+1, std::vector<int>(n+1, 0));
  for (int w = 2; w <= n; w++){
    for (int l = 0; l < n; l++){
      int r = l+w;
      if(r>n)continue;
      dp[l][r] = 100000000;
      for (int mid = l+1; mid < r; mid++){
        dp[l][r] = std::min(dp[l][r], dp[l][mid] + dp[mid][r] + data[l].first*data[mid].first*data[r-1].second);
      }
    }
  }
  std::cout << dp[0][n] << std::endl;
}