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;

int nlist[110];
int dp[110][110];

int main(){
  int n;
  cin>>n;
  for(int i=0;i<n;i++){
    cin>>nlist[i]>>nlist[i+1];
  }
  for(int i=1;i<n;i++){
    for(int j=0;j<n-i;j++){
      dp[j][j+i]=1<<30;
      for(int k=0;k<i;k++){
	dp[j][j+i]=min(dp[j][j+i],dp[j][j+k]+dp[j+k+1][j+i]+nlist[j]*nlist[j+k+1]*nlist[j+i+1]);
      }
    }
  }
  cout<<dp[0][n-1]<<endl;
  return 0;
}

C++: #include "bits/stdc++.h"
using namespace std;
typedef long long ll;
// #define int long long

template <class T>
bool INRANGE(T x, T a, T b) { return a <= x && x <= b; }

#define REP(i, n) for (int i = 0; i < (n); ++i)
#define RREP(i, n) for (int i = (n); i >= 0; --i)
#define FOR(i, a, b) for (int i = (a); i < (b); ++i)
#define RFOR(i, a, b) for (int i = (a); i >= (b); --i)
#define ALL(v) (v).begin(), (v).end()
#define RALL(a) (a).rbegin(), (a).rend()
#define debug(x) cerr << #x << " = " << (x) << " (L" << __LINE__ << ")" \
                      << " " << __FILE__ << endl;
#define DUMP(list) cout << "{ "; for(auto nth : list){ cout << nth << " "; } cout << "}" << endl;
typedef vector<int> vi;
typedef vector<string> vs;
typedef vector<vi> vvi;
typedef pair<int, int> pii;

int main() {
    cin.tie(0);
    ios::sync_with_stdio(false);

    int n;
    cin >> n;

    vi p(102);
    REP(i, n) cin >> p[i] >> p[i+1];
    vvi dp(102, vi(102, 0));

    FOR(l, 2, n+1){           // 対象とする行列の数
        FOR(i, 1, n-l+2){     
            int j = i + l - 1;   
            dp[i][j] = (1 << 20); // dp[i][j] := [Mi, Mj]の最小回数
            FOR(k, i, j){
	            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;

    
}

C++: #include <bits/stdc++.h>
using namespace std;
typedef long long ll;
const ll INF = 1e18;
const int inf = 1e9;
double pi = 3.14159265359;
#define rep(i, a, b) for (int i = a; i < b; i++)
#define per(i, b, a) for (int i = a - 1; i >= b; i--)
using Graph = vector<vector<int>>;
using pint = pair<int, int>;
int dx[4] = {1, 0, -1, 0}, dy[4] = {0, 1, 0, -1};
int dxx[8] = {1, 1, 1, 0, 0, -1, -1, -1}, dyy[8] = {-1, 0, 1, -1, 1, -1, 0, 1};

int main() {
    int n;
    cin >> n;
    int p[n + 1];
    rep (i, 1, n + 1) cin >> p[i - 1] >> p[i];
    int dp[n + 1][n + 1]; // i->jまでの計算をする時の最小回数
    rep (i, 0, n + 1) dp[i][i] = 0;
    rep (i, 2, n + 1) {
        rep (j, 1, n - i + 2) {
            int k = i + j - 1;
            dp[j][k] = inf;
            rep (l, j, k) {
                dp[j][k] = min (dp[j][k], dp[j][l] + dp[l + 1][k] +
                                              p[j - 1] * p[l] * p[k]);
            }
        }
    }
    cout << dp[1][n] << "\n";
}

C++: #include <iostream>
#include <cstdio>
#include <string>
#include <algorithm>
#include <utility>
#include <cmath>
#include <vector>
#include <queue>
#include <set>
#include <map>
#define rep(i, n) for(int i = 0; i < n; i++)
using namespace std;
typedef long long ll;
const ll mod = 1000000007;
const int INF = 1e9;

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

    int p[n+1];  // M_iはp[i]行p[i+1]列
    rep(i, n-1) {
        int ri, ci;
        cin >> ri >> ci;
        p[i] = ri; 
    }
    int rn, cn;
    cin >> rn >> cn;
    p[n-1] = rn, p[n] = cn;

    int dp[n][n];  // dp[i][j] : M_i・M_(i+1)・・・M_jの計算回数の最小値(i, jは0-index)
    rep(i, n) {
        rep(j, n) {
            if(i == j) {
                dp[i][j] = 0;
            }
            else {
                dp[i][j] = INF;
            }
        }
    }

    rep(j, n) {
        for(int i = n-1; i >= 0; i--) {
            if(j < i) {
                continue;
            }
            for(int k = i; k < j; k++) {
                dp[i][j] = min(dp[i][j], dp[i][k] + dp[k+1][j] + p[i]*p[k+1]*p[j+1]);
            }
        }
    }

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

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

static const int N = 100;

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

  for(i = 0 ; 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[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 NIL -1
#define INF 1000000001

using namespace std;

void minChainMultiple(vector<vector<int> > &minMultipleArray,const vector<int> &matSizeArray){
    int n = (int) minMultipleArray.size();
    for(int l = 1;l < n;l++){
        for(int i = 0;i < n-l;i++){
            int j = i+l;
            minMultipleArray[i][j] = INF;
            for(int k = i;k < j;k++){
                minMultipleArray[i][j] = min(minMultipleArray[i][j],
                minMultipleArray[i][k] + minMultipleArray[k+1][j]+matSizeArray[i]*matSizeArray[k+1]*matSizeArray[j+1]);
            } 
        }
    }
    
}

int main(){
    int n;
    int row,column;
    scanf("%d",&n);
    vector<int> matSizeArray(n+1,0);
    vector<vector<int> > minMultipleArray(n,vector<int>(n,0)); 

    for(int i = 0; i < n;i++){
        scanf("%d %d",&row,&column);
        matSizeArray[i] = row;
        matSizeArray[i+1] = column;
    }
    minChainMultiple(minMultipleArray,matSizeArray);
    printf("%d\n",minMultipleArray[0][n-1]);
    return 0;
}

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

using namespace std;

const int maxn=1e2+5;

int p[maxn],dp[maxn][maxn],n;

int main()
{
    scanf("%d",&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++){
        for(int i=1;i<=n-l+1;i++){
            int j=i+l-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;
}
/*
6
30 35
35 15
15 5
5 10
10 20
20 25
*/