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 long N = 100;

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

	for (long i = 1; i <= n; i++) m[i][i] = 0;
	for (long l = 2; l <= n; l++){
		for (long i = 1; i <= n - l + 1; i++){
			long j = i + l - 1;
			m[i][j] = (1 << 21);
			for (long k = i; k <= j - 1; k++){
				m[i][j] = min(m[i][j], m[i][k] + 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>

using namespace std;
#define fordebug int hoge;cin>>hoge;
#define DEKAI 1000000007
#define INF (1<<28)
#define lp(i,n) for(int i=0;i<n;i++)
#define lps(i,j,n) for(int i=j;i<n;i++)

#define int long long

signed main(){
	int n;
	cin>>n;
	int p[101],m[101][101];
	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]=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 <stdlib.h>
#include <stdio.h>

int MCM(int n){


int main(){

int i,n,m[100];

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

C++: #include <bits/stdc++.h>
using namespace std;
typedef long long ll;
const int limN = 105;

int xs[limN], ys[limN];
ll dp[limN][limN];
bool usd[limN][limN];

ll memo(int l, int r) {
    if(l>=r)
        return 0;
    if(usd[l][r])
        return dp[l][r];
    usd[l][r] = true;
    ll &ans = dp[l][r];
    ans = (1LL<<62);
    for(int i=l; i<r; i++) {
        // printf("%d %d %d\n", xs[l], ys[i], ys[i+1]);
        // printf("considerando %d %d %d => %d %lld %lld\n", l, i, r, xs[l]*ys[i]*ys[r], memo(l, i), memo(i+1, r));
        ans = min(ans, xs[l]*ys[i]*ys[r] + memo(l, i) + memo(i+1, r));
    }
    return ans;
}

int main() {
    int N ;
    scanf("%d", &N);
    for(int i=0; i<N; i++) {
        scanf("%d%d", &xs[i], &ys[i]);
    }
    printf("%lld\n", memo(0, N-1));
}

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

static const int N=100;

int main(){
  int i,l,j,k,n,p[N+1],m[N+1][N+1];
  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-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;
}

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 <map>
#include <set>
#include <list>
#include <cmath>
#include <queue>
#include <stack>
#include <cstdio>
#include <string>
#include <vector>
#include <complex>
#include <cstdlib>
#include <cstring>
#include <numeric>
#include <sstream>
#include <iostream>
#include <algorithm>
#include <functional>

#define mp       make_pair
#define pb       push_back
#define all(x)   (x).begin(),(x).end()
#define rep(i,n) for(int i=0;i<(n);i++)
#define repi(i,a,b) for(int i = (a); i < (b); i++)

using namespace std;

typedef    long long          ll;
typedef    unsigned long long ull;
typedef    vector<bool>       vb;
typedef    vector<int>        vi;
typedef    vector<vb>         vvb;
typedef    vector<vi>         vvi;
typedef    pair<int,int>      pii;

const int INF=1<<29;
const double EPS=1e-9;

const int dx[]={1,0,-1,0},dy[]={0,-1,0,1};
int n;//計算する行列の数
const int MAX_N =110;
int dp[MAX_N][MAX_N];//dp[i][j]:=Ai...Ajの計算に必要な最小のコスト
pii A[MAX_N];//行列firstを行secondを列とする。
int B[MAX_N+1][MAX_N+1]; //B[i][j]:=Ai...Ajに最適な括弧を挿入する場所
void init(){
	for(int i =0; i < n;i++){
		for(int j = 0;j < n;j++){
			dp[i][j]=INF;
			B[i][j]=0;
		}
	}
	for(int i =0;i < n;i++){
		dp[i][i]=0;
	}
}
//計算
int solve(){
	for(int k =1;k <n;k++){//個数
		for(int i =0;i <n-k;i++){//何処から始めるか
			for(int j =i;j <i+k;j++){//何処で終わるか
				int sz =A[i].first*A[j].second*A[i+k].second;
				int cost=dp[i][j]+dp[j+1][i+k]+sz;
				if(dp[i][i+k] >cost){
					dp[i][i+k]=cost;
					B[i][i+k]= j+1;//括弧を挿入する場所
				}

			}
		}
	}
	return dp[0][n-1];
}
//復元
void order(int i,int j){
	if(i==j){
		cout <<'A'<<i;
	}else{
		cout <<"(";
		order(i, B[i][j]-1);
		order(B[i][j], j);
		cout <<")";
	}
}

int main(){
	cin>>n;
	init();
	for(int i =0;i < n;i++){
		cin>>A[i].first>>A[i].second;
	}
	cout <<solve()<<endl;
	//order(0, n-1);
	return 0;
}

C++: #include<bits/stdc++.h>
using namespace std;
#define rep(i,n) for(int i = 0; i < (n) ; i++)
#define rrep(i,n) for(int i = n-1; i >= 0 ; i--)
constexpr auto INF = 2147483647;
typedef long long ll;

// void DebugGrid(int row, int column, auto table){
//   cout << endl;
//   rep(i,row){
//     rep(j,column) cout << table[i][j] << " ";
//     cout << endl;
//   }
// }

int main(){

  ll ans, n, DP[100][100];
  vector<pair<int,int>> matrix;
  cin >> n;
  rep(i,n){
    pair<int,int> inp;
    cin >> inp.first >> inp.second;
    matrix.emplace_back(inp);
  }

  rep(i,n)rep(j,n) DP[i][j] = INF;
  for(int l=0; l<n; l++)for(int i=0; i<n-l; i++){
    if(l == 0) DP[i][i] = 0;
    else{
      for(int j=i;j<=i+l;j++){
      DP[i][i+l] = min(DP[i][i+l],DP[i][j]+DP[j+1][i+l] + (matrix[i].first*matrix[j].second*matrix[i+l].second));
      }
    }
  }

  // DebugGrid(n,n,DP);
  cout << DP[0][n-1] << endl;
  return 0;
}