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 <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<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 <cstdlib>
#include <vector>
using namespace std;

struct matrix_size{
	int row;
	int col;
};

int matrixchaincost(vector <matrix_size> &M){
	int n=M.size();
	vector < vector <int> > cost(n, vector <int> (n));
	vector < vector <matrix_size> > X(n, vector <matrix_size> (n));
	for (int i=0; i<n; i++){
		cost[i][i] = 0;
		X[i][i] = M[i];
	}

	for (int length=2; length<=n; length++){
		for (int i=0; i+length<=n; i++){
			int j = i+length-1;
			X[i][j].row = X[i][i].row;
			X[i][j].col = X[j][j].col;
			if (X[i][j-1].col != X[j][j].row){
				cout<<"error"<<endl;
				return NULL;
			}
			int k = i+1;
			int mincost = X[i][k-1].row * X[i][k-1].col * X[k][j].col + cost[i][k-1] + cost[k][j];
			k++;
			while (k<=j){
				int tmp = X[i][k-1].row * X[i][k-1].col * X[k][j].col + cost[i][k-1] + cost[k][j];
				if (tmp<mincost)
					mincost = tmp;
				k++;
			};
			cost[i][j] = mincost;
		}
	}
	return cost[0][n-1];
}

int main(void){
	int n;
	cin>>n;

	vector <matrix_size> M(n);

	for (int i=0; i<n; i++){
		cin>>M[i].row;
		cin>>M[i].col;
	}
	cout<<matrixchaincost(M);
	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[k+1][j]+p[i-1]*p[k]*p[j]);
            }
        }
    }
    
    cout << m[1][n] << endl;
    
    return 0;
}

C++: #define _USE_MATH_DEFINES
#include <iostream>
#include <string>
#include <utility>
#include <stack>
#include <vector>
#include <queue>
#include <algorithm>
#include <map>
#include <climits>
#include <set>
#include <cmath>
#include <numeric>
#include <iomanip>

using namespace std;
int r[100];
int c[100];
int dp[100][100];
int main(void){
  int n;
  cin >> n;
  for(int i = 0; i < n; i++){
    cin >> r[i] >> c[i];
  }

  for(int i = 0; i < n; i++){
    for(int j = 0; j < n; j++){
      dp[i][j] = INT_MAX;
    }
  }
  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 - 1; j++){
      for(int k = j; k < j + i; k++){
        dp[j][j + i] = min(dp[j][j + i], dp[j][k] + dp[k + 1][j + i] + r[j] * c[k] * c[j + i]);
      }
    }
  }
  cout << dp[0][n - 1] << endl;
  return 0;
}

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

static const int N = 1000;
#define INF (1 << 20)

int p[N];
int m[N][N];

int main() {
    int n; std::cin >> n;
    for(int i = 1; i <= n; i++) {
        std::cin >> p[i-1] >> p[i];
    }
    for(int i = 0; i < N; i++) {
        for(int j = 0; j < N; j++) {
            m[i][j] = 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] = INF;
            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>
using namespace std;
int main(){
    int n;scanf("%d",&n);
    vector<pair<int,int>> m(n);
    for(int i=0;i<n;i++)scanf("%d%d",&m[i].first,&m[i].second);
    int dp[n][n];
    fill(dp[0],dp[0]+n*n,1e9);
    for(int i=0;i<n;i++)dp[i][i]=0;
    for(int k=1;k<n;k++){
        for(int i=0;i<n-k;i++){
            int j=i+k;
            for(int l=i;l<j;l++){
                dp[i][j]=min(dp[i][j],dp[i][l]+dp[l+1][j]+m[i].first*m[l].second*m[j].second);
            }
        }
    }
    printf("%d\n",dp[0][n-1]);
    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[k+1][j]+p[i-1]*p[k]*p[j]);
	    }
	}
    }
  cout<<m[1][n]<<endl;

  return 0;
}

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


int main(){
  int n;
  cin>>n;
  int a[105];
  for(int i=1;i<=n;i++)cin>>a[i-1]>>a[i];

  int dp[105][105]={};
  for(int i=0;i<105;i++)
    for(int j=0;j<105;j++)dp[i][j]=INF*(i!=j);

  for(int l=0;l<n;l++){
    for(int i=0;i<n-l;i++){
      int j=i+l;
      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;
}