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 <bits/stdc++.h>
using namespace std;
using ll = long long;
using vi = vector<int>;
using vvi = vector<vi>;
using vll = vector<ll>;
using pii = pair<int, int>;

#define rep(i, n) for (int i = 0; i < (int)(n); i++)

int solve(vector<vll> &c, vector<pii> &m, int s, int e1) {
  int e = e1 - 1;
  if (c[s][e1] != 0) return c[s][e1];
  
  if (e1 - s == 2) {
    c[s][e1] = m[s].first * m[s].second * m[e].second;
    return c[s][e1];
  }

  ll n_calc = LLONG_MAX;
  for (int i = s + 1; i < e1; i++) {
    ll total = 0;
    
    if (i - s > 1) {
      c[s][i] = solve(c, m, s, i);
      total += c[s][i];
    }
    
    if (e1 - i > 1) {
      c[i][e1] = solve(c, m, i, e1);
      total += c[i][e1];
    }

    total += m[s].first * m[i].first * m[e].second;
    
    n_calc = min(n_calc, total);
  }

  c[s][e1] = n_calc;
  return c[s][e1];
}

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

  vector<pii> m(n);
  rep(i, n) cin >> m[i].first >> m[i].second;

  if (n == 1) {
    cout << 0 << endl;
    return 0;
  }

  vector<vll> c(n + 1, vll(n + 1, 0));
  cout << solve(c, m, 0, n) << endl;
}

C++: #include<cstdio>
#include<iostream>
#include<cstring>
#include<algorithm>
using namespace std;
int dp[101][101],p[101];

int main(){
	int i,n,j,k,l;
	cin >> n;
	for( i = 0; i < n; i++ ){
        cin >> p[i] >> p[i+1];
	}
	for( i = 1; i <= n; i++ ) dp[i][i] = 0;
	for( l = 2; l <= n; l++ ){
        for( i = 1; i <= n-l+1; i++ ){
            j = i+l-1;
            dp[i][j] = (1 << 21);
            for( 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;
}

C++: #include <iostream>
#include <string>
#include <algorithm>
#include <vector>

using namespace std;
static const int N = 100;

#define INT_MIN     (-2147483647 - 1) /* minimum (signed) int value */
#define INT_MAX       2147483647    /* maximum (signed) int value */

void solve(vector<int> &data)
{
	vector<vector<int> > dp(N + 1, vector<int>(N + 1, 0));

	int nums = data.size() - 1;
	for (int len = 2; len <= nums; ++len)
	{
		for (int l = 1; l <= nums - len + 1; ++l)
		{
			int r = l + len - 1;
			dp[l][r] = INT_MAX;
			for (int m = l; m <= r - 1; ++m)
			{
				dp[l][r] = min(dp[l][r], dp[l][m] + dp[m+1][r] + data[l - 1] * data[m] * data[r]);
			}
		}
	}

	cout << dp[1][nums] << endl;
}

int main()
{
	int num; cin >> num;
	vector<int> data(num + 1);
	for (int i = 1; i <= num; ++i)
		cin >> data[i-1] >> data[i];

	solve(data);
}

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];

	scanf("%d", &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]);
				}
			}
		}

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

		return 0;
	}

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

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

  vector< vector<int> > dp(n + 1, vector<int>(n + 1));
  for (int l = 2; l <= n; ++l) {
    for (int i = 1; i <= n - l + 1; ++i) {
      int j = i + l - 1;
      dp[i][j] = 1000000000;
      for (int k = i; k < j; ++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;
}

C++: #include <iostream>
#include <string>
#define MAX 100001
#define SENTINEL 2000000000
using namespace std;

int m[101][101];
int p[101];

void mcm()
{
}

int main()
{
    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] = MAX;
            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>
#include <climits>
#define INF INT_MAX

using namespace std;

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

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

    return 0;
}

C++: #include <bits/stdc++.h>
#define rep(i,n) for(int i = 0; i < (int)(n); i++)
#define fi first
#define se second
#define pb push_back
#define eb emplace_back
#define sz(x) (int)(x).size()
using namespace std;
using ll = long long;
using P = pair<int, int>;
using vi = vector<int>;
using vc = vector<char>;
using vb = vector<bool>;
using vs = vector<string>;
using vll = vector<long long>;
using vp = vector<pair<int, int>>;
using vvi = vector<vector<int>>;
using vvc = vector<vector<char>>;
using vvll = vector<vector<long long>>;
template<class T> inline bool chmax(T &a, T b) { if (a<b) {a=b; return 1;} return 0;}
template<class T> inline bool chmin(T &a, T b) { if (b<a) {a=b; return 1;} return 0;}

const int INF = 1001001001;

int main() {
    ios::sync_with_stdio(false);
    cin.tie(0);
    
    int n;
    cin >> n;
    vi a(n+1);
    rep(i, n) {
        int r, c;
        cin >> r >> c;
        if (i == 0) {
            a[i] = r;
            a[i+1] = c;
        } else {
            a[i+1] = c;
        }
    }

    vvi dp(n+1, vi(n+1, INF));
    for (int i = 1; i <= n; ++i) dp[i][i] = 0;
    // kが間隔
    for (int k = 1; k <= n - 1; ++k) {
        // iが始点
        for (int i = 1; i + k <= n; ++i) {
            // jが間の点
            for (int j = i; j <= i + k - 1; ++j) {
                chmin(dp[i][i+k], dp[i][j] + dp[j+1][i+k] + a[i-1]*a[j]*a[i+k]);
            }
        }
    }

    // for (int i = 1; i <= n; ++i) {
    //     for (int j = i+1; j <= n; ++j) {
    //         for (int k = i; k <= j-1; ++k) {
    //             chmin(dp[i][j], dp[i][k] + dp[k+1][j] + a[i-1] * a[k] * a[j]);
    //         }
    //     }
    // }
    // だと更新順がダメ
    
    cout << dp[1][n] << endl;
}