Go: package main

import (
	"bufio"
	"fmt"
	"os"
	"strconv"
)

//util
var sc = bufio.NewScanner(os.Stdin)

func nextStr() string {
	sc.Scan()
	return sc.Text()
}

func nextInt() int {
	sc.Scan()
	i, e := strconv.Atoi(sc.Text())
	if e != nil {
		panic(e)
	}
	return i
}

func printList(list []int) {
	buf := bufio.NewWriter(os.Stdout)
	for _, v := range list {
		buf.Write([]byte(fmt.Sprintf(" %d", v)))
	}
	buf.Write([]byte("\n"))
	buf.Flush()
}

//solve
//単純な場合
func matrixChainMultiplication() {
	//行列が1つだけのとき
	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
			//kまでで区切る
			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])
			}
		}
	}
}

func max(a, b int) int {
	if a > b {
		return a
	} else {
		return b
	}
}

func min(a, b int) int {
	if a > b {
		return b
	} else {
		return a
	}
}

const MAX = 100

var n int
var p [MAX + 1]int

//m[i][j]: Mi * Mi+1 * ... * Mjを計算するときに必要なスカラー乗算の最小回数
var m [MAX + 1][MAX + 1]int

func main() {
	sc.Split(bufio.ScanWords)
	n = nextInt()
	for i := 1; i <= n; i++ {

		p[i-1] = nextInt() //行数
		p[i] = nextInt()   //列数
	}

	matrixChainMultiplication()
	fmt.Println(m[1][n])
}

C++: // 連鎖行列積 問題
#include<cstdio>
#include<cstdlib>
#include<cstring>
#include<stack>
#include<algorithm>
#include<iostream>
#include<cmath>
#include<vector>

using namespace std;

#define MAX_N 100
#define ELE_NUM 2
// 無効な値の定義
const int INV = -1;

const int colNo = 0;
const int rowNo = 1;
const int IntMAX = 	2147483647;

int ChainedMatrixtMultiplication(int n, int m, int matrixData[][ELE_NUM]);

int main(void)
{

    int n, count;
    int matrix_data[MAX_N + 1][ELE_NUM];

    cin >> n;

    for(int i = 1; i <= n; i++)
    {
        // 行
        cin >> matrix_data[i][colNo];
        // 列
        cin >> matrix_data[i][rowNo];
    }

    count = ChainedMatrixtMultiplication(n, ELE_NUM, matrix_data);
    printf("%d\n", count);

    return 0;
}

// 連鎖行列積の最小の乗算回数を演算する関数
// n : 積を求める行列の数
// m : 行列の情報 : 0 - 行の情報, 1 - 列の情報
// matrixData[][] : 各行列の行、列情報を保持する配列
int ChainedMatrixtMultiplication(int n, int m, int matrixData[][ELE_NUM])
{

    // 第1要素 : 演算開始のNo., 第2要素 : 演算終了のNo.
    int dp[MAX_N + 1][MAX_N + 1];
    int calcResult = 0;

    // 配列の初期化
    for(int i = 0; i <= n; i++)
    {
        for(int j = 0; j <= n; j++)
        {
            dp[i][j] = INV;

            if( i == j )
            {
                // 同じ要素同士の積は演算することが不可能
                dp[i][j] = 0;
            }
        }
    }

    // 行列の演算回数の計算
    for(int l = 2; l <= n; l++)
    {
        for(int i = 1; i <= n - l + 1; i++)
        {
            int j = i + l - 1;

            dp[i][j] = IntMAX;

            for(int k = i; k <= j - 1; k++)
            {
                // 3つ以上の要素の積の時
                calcResult = dp[i][k] + dp[k + 1][j]
                            + ( matrixData[i][colNo] * matrixData[k][rowNo] * matrixData[j][rowNo]);

                dp[i][j] = min( dp[i][j], calcResult );
            }
        }
    }

    return dp[1][n];
}

C++: #define _CRT_SECURE_NO_WARNINGS
#include <bits/stdc++.h>
#define INFTY (1<<21)
using namespace std;

static const int N = 100;

int main() {
	int p[N + 1], m[N + 1][N + 1];
	int n;
	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] = INFTY;
			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;
}

C++: 
#include <bits/stdc++.h>

#define PI 3.141592653
#define rep(i,a,n) for(int i=a;i<(int)n;++i)
#define SZ(x) ((int)(x).size())	//size() unsigned -> int
#define descSort(a) sort(a.begin(),a.end(),std::greater<int>())
using namespace std;
typedef long long ll;
const ll INF = 1e9 + 7;
ll gcd(ll x,ll y){
    if(x%y==0)return y;
    return gcd(y,x%y);
}

int main(void){
    int n;
    cin>>n;
    int p[101],m[101][101];
    rep(i,1,n+1)cin>>p[i-1]>>p[i];
    rep(i,1,n+1)m[i][i]=0;
    rep(l,2,n+1){
        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]=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<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<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<iostream>
using namespace std;
int main() {
    cin.tie(0);
    ios::sync_with_stdio(false);
    int n;
    cin>>n;
    int d[n+1];
    for(int i=0;i<n;++i) cin>>d[i]>>d[i+1];
    int a[n][n];
    fill(a[0],a[n],1<<28);
    for(int i=0;i<n;++i) a[i][i]=0;
    for(int l=1;l<n;++l)
        for(int i=0;i<n-l;++i){
            int j=i+l;
            for(int k=i;k<j;++k)
                a[i][j]=min(a[i][j],a[i][k]+a[k+1][j]+d[i]*d[k+1]*d[j+1]);
        }
    cout<<a[0][n-1]<<endl;
}

C++: #include<iostream>
#include<vector>
#include<algorithm>
#define INF (1<<21)
using namespace std;

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

  vector<int> p(105);
  int m[105][105];

  for(int i = 1; i <= n; i++){
    cin >> p[i-1] >> p[i];
    m[i][i] = 0;
  }

  for(int i = 2; i <= n; i++){
    for(int j = 1; j <= n-i+1; j++){
      int x = i + j - 1;
      m[j][x] = INF;

      for(int k = j; k <= x-1; k++){
	m[j][x] = min(m[j][x], m[j][k]+m[k+1][x] + p[j-1]*p[k]*p[x]);
      }
    }
  }

  cout << m[1][n] << endl;

  return 0;

}

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


int main() {
	int n, p[101], m[101][101];
	cin >> n;
	for (int i = 1; i <= n; i++) cin >> p[i - 1] >> p[i];
	
	int i, j, k, l;
	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;

	
}

C++: #include <iostream>
#include <vector>
using namespace std;
const int INF = 1001001001;

int main(){
    int n;
    cin >> n;
    vector<int> rnum(n+1);
    for(int i = 0; i < n; i++){
        cin >> rnum[i] >> rnum[i+1];
    }

    vector<vector<int>> memo(n, vector<int>(n, INF));
    for(int i = 0; i < n; i++) memo[i][i] = 0;

    for(int i = n-1; i >= 0; i--){
        for(int j = i; j < n; j++){
            for(int k = i; k+1 < n; k++){
                if(memo[i][j] > memo[i][k] + memo[k+1][j] + rnum[i]*rnum[k+1]*rnum[j+1]){
                    memo[i][j] = memo[i][k] + memo[k+1][j] + rnum[i]*rnum[k+1]*rnum[j+1];
                }
            }
        }
    }

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