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<stdio.h>
#include<cstdio>
#include<string>
#include<algorithm>

#define INF 100000001
using namespace std;

int DP[101][101];
int *p;

int rec(int r, int c) {
	int Min = INF;
	int num = c-r;
	
	for(int i= 0; i< num; i++) {
		Min = min(Min , DP[r][r+i] + DP[r+i+1][c] + p[r-1]*p[r-1]*p[r+i]*p[c]);
	}
	return Min;
}

int main() {
	int N; 
	cin >> N;
	for(int i=1; i <= N; i++) DP[i][i] =0;
	
	p=(int *)malloc(sizeof(int) * (N+1));
	
	cin >>p[0];
	cin >> p[1];
	int bb;
	for(int i = 1; i <= N; i ++) {
	
	cin >> bb;
	cin >> p[i];
	}
	for(int i =1; i < N; i++) DP[i][i+1] = p[i-1]*p[i] *p[i+1];
	
	for(int j=0; j <=N-3; j++) {
		for(int i = 3+j; i <=N; i++) {
			DP[i-2-j][i] = rec(i-2-j,i);
			}
			}
			cout << DP[1][N] << endl;
			return 0;
			}

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

int min(int n1,int n2){
  if(n1>=n2) return n2;
  else return n1;
}

int main()
{
  int n,r,l,i,j,k;
  
  scanf("%d",&n);
  
  for(i=1;i<=n;i++){
    scanf("%d %d",&p[i-1],&p[i]);
  }
  
  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[i][k]+m[k+1][j]+p[i-1]*p[k]*p[j]);
      }
    }
  }
  
  printf("%d\n",m[i][j]);
  
  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[i][k]+m[k+1][j]+p[i-1]*p[k]*p[j]);
        }
    }
  }
  cout << m[1][n] << endl;
  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 ( 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 <iostream>
#include <vector>
#include <algorithm>

typedef struct {
	int row;
	int column;
}Matrix;

const int MaxN = 100;

int dp[MaxN + 1][MaxN + 1];

int calc(std::vector<Matrix>& m, int a, int b)
{
	int ans;

	if (b - a == 0) {
		return 0;
	}
	if (b - a == 1) {
		if (dp[a][b] != 0) {
			return dp[a][b];
		}
		else {
			ans = m[a - 1].row*m[b - 1].column*m[a - 1].column;
			dp[a][b] = ans;
			return ans;
		}
	}
	else {
		if (dp[a][b] != 0) {
			return dp[a][b];
		}

		ans = calc(m, a, a) + calc(m, a + 1, b) + m[a - 1].row*m[b - 1].column*m[a - 1].column;
		for (int i = 1; i < b - a; i++) {
			int temp;
			temp = calc(m, a, a + i) + calc(m, a + i + 1, b) + m[a - 1].row*m[b - 1].column*m[a + i - 1].column;
			if (temp < ans) {
				ans = temp;
			}
		}
		dp[a][b] = ans;
	}

	return ans;
}

int main()
{
	int n;
	Matrix temp;
	std::vector<Matrix> m;
	
	std::cin >> n;

	for (int i = 0; i < n; i++) {
		std::cin >> temp.row >> temp.column;
		m.push_back(temp);
	}

	std::cout << calc(m, 1, m.size()) << std::endl;

	return 0;
}

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

long long INF = 10000000000;

int main(){
    //input
    long long n;
    cin >> n;
    long long r[n+1], c[n+1];
    long long i;
    for(i = 1; i <= n; i++){
        cin >> r[i] >> c[i];
    }

    //calc
    long long dp[n+1][n+1];
    for(i = 1; i <= n; i++){
        dp[i][i] = 0;
    }
    long long j,d;
    for(d = 1; d <= n-1; d++){
        for(i = 1; i <= n-d; i++){
            dp[i][i+d] = INF;
            for(j = 0; j < d; j++){
                dp[i][i+d] = min(dp[i][i+d], dp[i][i+j] + r[i]*c[i+j]*c[i+d] + dp[i+j+1][i+d]);
            }
        }
    }

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

C++: #include <iostream>
#define INF 100001

using namespace std;

int main(){
  int n;
  cin >> n;
  int dp[n+1][n+1],p[n+1];
  cin >> p[0] >> p[1];
  for(int i=2;i<=n;i++){
    int t; cin >> t;
    cin >> p[i];
  }
  for(int i=1;i<=n;i++) dp[i][i]=0;
  for(int l=2;l<=n;l++){
    for(int i=1;i<=n-l+1;i++){
      int j=i+l-1;
      dp[i][j]=INF;
      for(int k=i;k<=j-1;k++)
        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] << endl;
}