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++: #include <iostream>
#include <bits/stdc++.h>
#define index indexxx
using namespace std;
int n;
int p[10000],m[1000][1000];
int index;
int fun(int left,int right)
{
	if(m[left][right]!=0)
		return m[left][right]; 
	if(left==right){
		return 0;
	}
	int i=left,j=right;
	int u=fun(left,left)+fun(left+1,right)+p[i-1]*p[i]*p[j];
	for(int k=i+1;k<j;k++){//遍历
		int t=fun(i,k)+fun(k+1,right)+p[i-1]*p[k]*p[j]; 
		if(t<u)
		{
			u=t;
		}
	}
	m[left][right]=u;
	return u;
}

int main(void)
{
	cin>>n;
	scanf("%d",p+(index++));
	scanf("%d",p+(index++));
	int tmp,x;
	for(int i=1;i<n;i++){
		scanf("%d",&x);
		scanf("%d",p+(index++));
	}
	printf("%d\n",fun(1,n));
	return 0;
}

C++: #include<cstdio>
#include<cstdlib>
#include<cstring>
#include<cmath>
#include<climits>
#include<iostream>
#include<sstream>
#include<utility>
#include<map>
#include<vector>
#include<queue>
#include<algorithm>
#include<set>
#include<stack>
using namespace std;
typedef long long ll;
typedef pair<int,int>P;
int N;
int r[105],c[105];
ll dp[105][105]={0};

void dbg()
{
	for(int i=0;i<N;i++,puts(""))
		for(int j=0;j<N;j++)
			printf("%7d ",dp[i][j]);
}

int main()
{
	scanf("%d",&N);
	for(int i=0;i<N;i++)
		scanf("%d%d",&r[i],&c[i]);
	for(int i=0;i<N;i++)dp[i][i]=0;
	for(int l=1;l<N;l++)
		for(int i=0;i<N-l;i++)
		{
			int j=i+l;
			dp[i][j]=1e20;
			for(int k=0;k<j;k++)
				dp[i][j]=min(dp[i][j],dp[i][k]+dp[k+1][j]+r[i]*c[k]*c[j]);
		}
	printf("%lld\n",dp[0][N-1]);
	return 0;
}

C++: #include<algorithm>
#include<iostream>
#include<vector>
#include<string>
#include<queue>
#include<stack>
#include<cmath>
#include<list>
#include<set>
#include<map>

using namespace std;
int p[100], m[100 + 1][100 + 1];

void matrixChainMultiplication(int n) {
	for (int i = 0; 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]);
			}
		}
	}
}

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

	matrixChainMultiplication(N);
	cout << m[1][N] << endl;
	return 0;
}

C++: #include <iostream>
#include <vector>
#include <utility>
#include <map>
//#include "../cxx-prettyprint/prettyprint.hpp"
using std::vector;
using std::pair;

std::map<vector<pair<int, int>>, int> memo;

int get_minimum_multiplication(vector<pair<int, int>> matrix_sizes) {
    if (matrix_sizes.size() == 1) {
        return 0;
    } else if (matrix_sizes.size() == 2) {
        return matrix_sizes[0].first * matrix_sizes[0].second * matrix_sizes[1].second;
    } else if (memo.find(matrix_sizes) != memo.end()) {
        return memo[matrix_sizes];
    } else {
        int min_count = 0;
        for (int i = 1; i < matrix_sizes.size(); i ++) {
            vector<pair<int, int>> left, right;
            std::copy(matrix_sizes.begin(), matrix_sizes.begin() + i, std::back_inserter(left));
            std::copy(matrix_sizes.begin() + i, matrix_sizes.end(), std::back_inserter(right));
            int min_count_left = get_minimum_multiplication(left);
            int min_count_right = get_minimum_multiplication(right);
            int count = min_count_left +
                        min_count_right +
                        left.front().first * left.back().second * right.back().second;
            if (min_count == 0) {
                min_count = count;
            } else {
                min_count = std::min(min_count, count);
            }
        }
        memo[matrix_sizes] = min_count;
        return min_count;
    }
}

int main() {
    int n;
    std::cin >> n;
    vector<pair<int, int>> matrix_sizes(n);
    for (auto& size : matrix_sizes) {
        std::cin >> size.first >> size.second;
    }

    std::cout << get_minimum_multiplication(matrix_sizes) << std::endl;
}

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

static const int N = 100;
#define EXTREME 10000000;
int S[N+1][N+1];
int p[N+1];

void multiply(int n){
    int i;
    for(i = 1; i <= n; i++){
        S[i][i] = 0;
    }

    for(int l = 2; l <= n; l++){
        for(int i = 1; i <= n - l + 1; i++){
            int j = i + l - 1;
            S[i][j] = EXTREME;
            for(int k = i; k <= j - 1; k++){
                S[i][j] = min(S[i][j], S[i][k] + S[k+1][j] + p[i-1]*p[k]*p[j]);
            }
        }
    }
}

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


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

    }

    multiply(n);
    cout << S[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 N ;
int a[101][101];
int m[101][2];

int main() {
    cin >> N;
    for (int i = 1; i <= N; ++i) {
        cin >> m[i][0] >> m[i][1];
    }

    for (int j = 1; j <= N; ++j) {
        a[j][j] = 0;
    }

    for (int k = 1; k < N; ++k) {
        for (int l = 1; l <= N- k ; ++l) {
            int j = l + k;
            int mn = INT_MAX;
            for (int p = l; p <= j-1 ; ++p) {
                mn = min(mn, a[l][p] + a[p+1][j] + m[l][0] * m[p][1] * m[j][1]);
            }
            a[l][j] = mn;
        }
    }
    cout << a[1][N] << endl;

    return 0;
}

C++: #include <stdio.h>
#include <algorithm>
using namespace std;

typedef long long ll;
#define INF ((ll)10000000000)
#define MAX_N (110)
typedef struct {
    ll r;
    ll c;
} Mat;

int n;
Mat M[MAX_N];
ll dp[MAX_N][MAX_N];

ll dfs(int i, int j)
{
    if ( j - i == 1 ) return 0;
    else if ( dp[i][j] ) return dp[i][j];
    else {
	ll ret = INF;
	for ( int k = i + 1; k < j; k++ ) {
	    ret = min(ret, dfs(i, k) + dfs(k, j) + M[i].r * M[k].r * M[j-1].c );
	}

	return dp[i][j] = ret;
    }
}

int main()
{
    scanf("%d", &n);

    for ( int i = 0; i < n; i++ ) {
	scanf("%lld %lld", &M[i].r, &M[i].c);
    }
    
    ll ans = dfs( 0, n );
    printf("%lld\n", ans);

    return 0;
}