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<algorithm>
using namespace std;
static const int N=100;

int main(){
    int n,a[N+1],b[N+1][N+1];
    cin >> n;
    for(int i=1;i<=n;i++){
        cin >> a[i-1] >> a[i]; 
    }
    
    for(int i=1;i<=n;i++) b[i][i]=0;
    for(int k=2;k<=n;k++){
        for(int i=1;i<=n-k+1;i++){
            int j=i+k-1;
            b[i][j]=(1<<21);
            for(int m=i;m<=j-1;m++){
                b[i][j]=min(b[i][j],b[i][m]+b[m+1][j]+a[i-1]*a[m]*a[j]);
            }
        }
    }
    
    cout << b[1][n] << endl;
    return 0;
}

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

static const in N = 100;

int main(){
  int n,p[N+1],m[N+1][N+1];
  cin>>n;

  for(int i = 0;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++){
      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 ll long long
#define rep(i, n) for(int i=0;i<(n);++i)
#define per(i, n) for(int i=(n)-1;i>=0;--i)
#define repa(i, n) for(int i=1;i<(n);++i)
#define foreach(i, n) for(auto &i:(n))
#define pii pair<int, int>
#define pll pair<long long, long long>
#define all(x) (x).begin(), (x).end()
#define bit(x) (1ll << (x))
const ll MOD = (ll)1e9+7;
const int INF = (ll)1e9+7;
const ll INFLL = (ll)1e18;
using namespace std;
template<class t>
using vvector = vector<vector<t>>;
template<class t>
using vvvector = vector<vector<vector<t>>>;
template<class t>
using priority_queuer = priority_queue<t, vector<t>, greater<t>>;
template<class t, class u> bool chmax(t &a, u b){if(a<b){a=b;return true;}return false;}
template<class t, class u> bool chmin(t &a, u b){if(a>b){a=b;return true;}return false;}

ll modpow(ll x, ll b){
	ll res = 1;
	while(b){
		if(b&1)res = res * x % MOD;
		x = x * x % MOD;
		b>>=1;
	}
	return res;
}

ll modinv(ll x){
	return modpow(x, MOD-2);
}

int n;
vector<pll> line;
vvector<ll> dp;

ll func(int l, int r){
	if(l==r)return 0;
	if(dp[l][r]>=0)return dp[l][r];
	ll res = INFLL;
	for(int mid=l;mid<r;++mid){
		chmin(res, func(l, mid) + func(mid+1, r) + line[l].first * line[mid].second * line[r].second);
	}
	return dp[l][r] = res;
}

int main(){
	cin >> n;
	line.resize(n);
	dp.resize(n, vector<ll>(n, -1));
	foreach(i, line)cin>>i.first>>i.second;
	cout << func(0, n-1) << endl;
	return 0;
}

C++: #include<bits/stdc++.h>
using namespace std;
#define INF 100000000
int n,m[101][101],p[101];
void dp();

int main(){
  cin>>n;
  for(int i=0;i<n;i++)cin>>p[i-1]>>p[i];
  dp();
  cout<<m[1][n]<<endl;
  return 0;
}
void dp(){
  for(int i=0;i<n-1;i++)
    for(int j=1;j<n-i;j++){
     int a=j+i+1;
     m[j][a]=INF;
     for(int k=j;k<a;k++){
       int b=m[j][k]+m[k+1][a]+p[j-2]*p[k-1]*p[a-1];
       if(m[j][a]>b)m[j][a]=b;
     }
    } 
}

C++: #include <iostream>
#include <string>
#include <climits>
using namespace std;
const int INFY = INT_MAX;
int p[101], M[101][101];

void matrixCahinOrder(int length){
    int n = length - 1;
    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] = INFY;
            for (int k = i; k <= j-1; k++){
                int q = M[i][k] + M[k+1][j] + p[i-1]*p[k]*p[j];
                M[i][j] = min(M[i][j], q);
            }
        }
    }
}
int main(int argc, char* argv[]) {
    int n, tmp;
    cin >> n;
    for (int i = 0; i < n; i++){
            cin >> p[i] >> tmp;
    }
    p[n] = tmp;

    /*
    for (int i = 0; i <= n; i++){
        cout << p[i] << endl;
    }
    */
    matrixCahinOrder(n+1);
    cout << M[1][n] << endl;
    return 0;
}

C++: #include "stdio.h"
#include<iostream>
#include<algorithm>

#define INFINITY 10000000

using namespace std;


int main(void){

  int N;
  scanf("%d",&N);
  
  int* p = new int [N+1];

  int** m = new int* [N+1];
  for(int i=0;i<N+1;i++){
    m[i] = new int [N+1];
  }

  for(int i=1;i<=N;i++){
    scanf("%d %d", &p[i-1], &p[i]);
  }

  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] = INFINITY;
      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]);
      }
    
    }
  
  }

  printf("%d\n", m[1][N]);

  delete [] p;
  for(int i=0;i<N+1;i++){
    delete [] m[i];
  }
  delete [] m;


  return 0;
}

C++: #include <iostream>
#include <set>
#include <vector>
#include <utility>

using namespace std;

typedef long long signed int ll;

constexpr ll NIL = -20000000000;

vector<pair<int, int>> w;
ll dp[100][100];

ll mmc(int b, int e) {
    if (e == b + 1 || e == b) return 0;
    if (!dp[b][e]) {
        dp[b][e] = -NIL;
        for (int i = b + 1; i < e; i++) {
            dp[b][e] = min(dp[b][e], mmc(b, i) + mmc(i, e) + w[b].first * w[i].first * w[e - 1].second);
        }
    }
    return dp[b][e];
}

int main() {
    int n;
    cin >> n;
    for (int i = 0; i < n; i++) {
        int x, y;
        cin >> x >> y;
        w.push_back(make_pair(x, y));
    }
    cout << mmc(0, n) << endl;
}

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;
}