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;
#define rep(i, n) for (int i = 0; i < (int)(n); i++)

int main() {
	int n;
  	cin >>n;
  	long int p[n+1];
  	rep(i,n){
    	cin >>p[i]>>p[i+1];    
    }
  	long int dp[n+1][n+1];
  	for(int i=1;i<=n;i++){
    	dp[i][i]=0;
    }
  	
  	for(int l=1;l<=n-1;l++){
    	for(int i=1;i<=n-l;i++){
        	int j=i+l;
          	dp[i][j]=1000000000;
            for(int k=i;k<=j;k++){
              long int x=dp[i][k]+dp[k+1][j]+p[i-1]*p[k]*p[j];
             dp[i][j]=min(dp[i][j],x);    	
        	}             
            
        }
    }
  	cout<<dp[1][n]<<endl;
  
}

C++: #include<stdio.h>
#define INFTY 1000000

int min(int,int);

int main(){
  int l,i,j,k,n,p[100],m[101][101],q;
  scanf("%d",&n);

  for(i=1;i<=n;i++){
    scanf("%d%d",&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]=INFTY;
      for(k=i;k<=j-1;k++){
	q=m[i][k]+m[k+1][j]+p[i-1]*p[k]*p[j];
	m[i][j]=min(m[i][j],q);
      }
    }
  }

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

int min(int a,int b){
  if(a<b)return a;
  else return b;
}

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<cstdio>
#include<algorithm>
#include<cstring>
using namespace std;
#define INFTY (1<<30)

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

void multiplyMatrix(){
	int i, l, j, k;
	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] = INFTY;
			for(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]);
		}
	}
}

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

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

#define MAX 100

int dp[MAX+1][MAX+1]; //乗算回数
int p[MAX+1]; 

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

    for(int i = 1; i <= n; i++){
        cin >> p[i-1] >> p[i];
    }

    for(int i = 1; i <= n; i++) dp[i][i] = 0;

    for(int l = 2; l <= n; l++){  //lは対象とする行列の数
        for(int i = 1; i + l - 1 <= n; i++){
            int j = i + l - 1; //iからjまでの最小乗算回数を見ていく
            dp[i][j] = (1 << 21); //INFTYで埋める
            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;

    return 0;
}

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

static const int N=100;
int dp[N+1][N+1];
int p[N+1];
int main(){
    int n;
    cin>>n;
    int h,w;//h:num of gyo,w:num of retu
    for(int i=1;i<=n;i++){
        cin>>p[i-1]>>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=l+i-1;
            dp[i][j]=(1<<21);
        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;
    return 0;
}

C++: #include<bits/stdc++.h>
using namespace std;
template<class T>bool chmin(T &a, const T &b) { if (b<a) { a=b; return 1; } return 0; }

const int INF = 1e8;
int main() {
	int n;
	cin >> n;
	vector<int> r(n),c(n);
	for(int i=0; i<n; i++){
		cin >> r.at(i) >> c.at(i);
	}
	
	vector<vector<int>>dp(n,vector<int>(n,INF));
	for(int i=0; i<n; i++) dp.at(i).at(i) = 0;
	for(int w=1; w<=n-1; w++){
		for(int l=0; l+w<n; l++){
			if(w==1) dp.at(l).at(l+w) = r.at(l)*c.at(l+w)*c.at(l); 
			for(int mid=l; mid<l+w; mid++){
				chmin( dp.at(l).at(l+w), dp.at(l).at(mid) + dp.at(mid+1).at(l+w) + r.at(l)*c.at(l+w)*c.at(mid));
			}
		}
	}
	cout << dp.at(0).at(n-1) << endl;
}

C++: #include<cstdio>
#include<iostream>
#include<algorithm>
using namespace std;
int dp[105][105];
int p[105];
void calcu(int n)
{
  for(int i=0; i<=n; i++) dp[i][i] = 0;
  for(int num=2; num<=n; num++)// num to control the number of matrix involved in multiplication.
  {
    for(int i=1; i<=n-num+1; i++)
    {
      int j = i+num-1;
      dp[i][j] = (1 << 30);
      for(int k=i; k<j; k++)
      {
        dp[i][j] = min(dp[i][j], dp[i][k] + dp[k+1][j] + p[i-1]*p[k]*p[j]);
      }
    }

  }
  printf("%d\n", dp[1][n]);
}
int main()
{
  int n;
  scanf("%d", &n);
  for(int i=1; i<=n; i++)
  {
    scanf("%d%d", &p[i-1], &p[i]);
  }
  calcu(n);

  return 0;
}

C++: #include <iostream>
#include <vector>
#define MAX 10000001
using namespace std;

int main() {
    int num;
    cin >> num;
    int array[101][101];

    for(int i=0; i<=num; i++) {
        array[i][i] = 0;
    }

    vector<int> p;
    for(int i=0; i<num; i++) {
        int row, col;
        cin >> row >> col;
        if(i==0) p.push_back(row);
        p.push_back(col);
    }

    for(int l=0; l<num; l++) {
        for(int i=0; (i+l+1)<num; i++) {
            int j=i+l+1;
            array[i][j] = MAX;
            for(int k=i+l; k>=i; k--) {
                int value = array[i][k]+array[k+1][i+l+1]+(p[i]*p[k+1]*p[i+l+2]);
                array[i][j] = min(array[i][j],value);
            }
        }
    }
    cout << array[0][num-1] << endl;
}

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

int main()
{
	int i,j,k,l,m[101][101],p[101],n;
	
	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;
}