Go: package main

import (
	"bufio"
	"fmt"
	"os"
	"strconv"
	"strings"
)

var scanner = bufio.NewScanner(os.Stdin)

func nextString() string {
	scanner.Scan()
	return scanner.Text()
}

func nextInt() int {
	n, err := strconv.Atoi(nextString())
	if err != nil {
		fmt.Printf("strconv.Atoi failed: %v\n", err)
	}
	return n
}

func min(x, y int) int {
	if x < y {
		return x
	}
	return y
}

func stringifyArray(arr []int) string {
	return strings.TrimRight(fmt.Sprintf("%+v", arr)[1:], "]")
}

func main() {
	scanner.Split(bufio.ScanWords)

	n := nextInt()
	m := make([][]int, n)
	sizes := make([][]int, n)
	for i := 0; i < n; i++ {
		sizes[i] = []int{nextInt(), nextInt()}
		m[i] = make([]int, n)
	}
	// fmt.Println(sizes)

	for w := 1; w < n; w++ {
		for i := 0; i < n-w; i++ {
			j := i + w
			minBetweenIandJ := 10000000
			for k := i; k < j; k++ {
				// fmt.Println(i, j, k, m[i][k], m[k+1][j], sizes[i][0]*sizes[k][1]*sizes[j][1])
				minBetweenIandJ = min(minBetweenIandJ, m[i][k]+m[k+1][j]+sizes[i][0]*sizes[k][1]*sizes[j][1])
			}
			m[i][j] = minBetweenIandJ
		}
	}
	// for i := 0; i < len(m); i++ {
	// 	fmt.Println(stringifyArray(m[i]))
	// }
	fmt.Println(m[0][n-1])
}

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

int	main()
{
	int	cnt[100][100];
	int	n;
	cin >> n;
	for (int i = 0; i < n; ++i) {
		for (int j = 0; j < n; ++j)
			cnt[i][j] = -1;
		cnt[i][i] = 0;
	}
	vector<int>	r_vec(n), c_vec(n);
	for (int i = 0; i < n; ++i)
		cin >> r_vec.at(i) >> c_vec.at(i);
	for (int i = 1; i < n; ++i) {
		int	k;
		for (int j = 0; (k = i + j) < n; ++j) {
			for (int l = j; l < k; ++l) {
				int	tmp_cnt = cnt[j][l] + cnt[l + 1][k];
				tmp_cnt += r_vec.at(j) * c_vec.at(l) * c_vec.at(k);
				if (cnt[j][k] == -1 || cnt[j][k] > tmp_cnt)
					cnt[j][k] = tmp_cnt;
			}
		}
	}
	cout << cnt[0][n - 1] << endl;
}

C++: #include<cstdio>
#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-1+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;

using ll = long long;
using ld = long double;
using P = pair<string, int>;
constexpr ld EPS = 1e-12;
constexpr int INF = numeric_limits<int>::max() / 2;
constexpr int MOD = 1e9 + 7;

template <typename T>
void printv(const vector<T> &v)
{
    int sz = v.size();
    for (int i = 0; i < sz; i++)
    {
        cout << v[i] << " \n"[i == sz - 1];
    }
}

int n;
vector<ll> r(100), c(100);
ll dp[100][100];

// dp[l][r]
ll calc(int lx, int rx)
{
    if (dp[lx][rx] != 1e15)
    {
        return dp[lx][rx];
    }
    for (int i = lx; i < rx; i++)
    {
        dp[lx][rx] = min(dp[lx][rx], calc(lx, i) + calc(i + 1, rx) + r[lx] * c[i] * c[rx]);
    }
    return dp[lx][rx];
}

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

    cin >> n;
    for (int i = 0; i < n; i++)
        cin >> r[i] >> c[i];
    for (int i = 0; i < n; i++)
    {
        dp[i][i] = 0;
        for (int j = i + 1; j < n; j++)
        {
            dp[i][j] = 1e15;
        }
    }
    cout << calc(0, n - 1) << endl;
}

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

int main()
{
	int n;
	int v[101];
	long m[100][100];
	const long nil = 999999999;

	cin >> n;

	for (int i = 0; i < n; i++)
		cin >> v[i] >> v[i + 1];

	for (int i = 0; i < 100; i++)
		for (int j = 0; j < 100; j++)
			if (i == j)
				m[i][j] = 0;
			else
				m[i][j] = nil;
	
	for(int i = n - 2; i > -1; i--)
		for(int j = i + 1; j < n; j++)
			for (int k = i; k < n; k++)
				m[i][j] = min(m[i][j], m[i][k] + m[k + 1][j] + v[i] * v[k + 1] * v[j + 1]);

	cout << m[0][n - 1] << endl;

	return 0;
}

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

struct mat {
	ll l, c, r;
};

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

	mat a[110][110];
	int N; cin >> N;
	ll l, r;
	for (int i = 0; i < N; i++) {
		cin >> l >> r;
		a[i][i].l = l;
		a[i][i].r = r;
		a[i][i].c = 0;
	}
	for (int l = 1; l < N;l++) {
		for (int i = 0; i+l < N; i++) {
			ll m = 1000010;
			a[i][i + l].l = a[i][i].l;
			a[i][i + l].r = a[i + l][i + l].r;
			for (int j = i; j < i + l; j++) {
				m = min(a[i][j].l * a[i][j].r * a[j + 1][i + l].r + a[i][j].c + a[j + 1][i + l].c, m);
			}
			a[i][i + l].c = m;
		}
	}
	cout << a[0][N-1].c << endl;
}

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

static const int N = 1000;

int main()
{
    int n, p[N + 1];
    vector<vector<int>> m(N + 1, vector<int>(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.at(i).at(i) = 0;
    }
    for (int l = 2; l <= n; l++)
    {
        for (int i = 1; i <= n - 1; i++)
        {
            int j = i + l - 1;
            m.at(i).at(j) = (1 << 21);
            for (int k = i; k <= j - 1; k++)
            {
                m.at(i).at(j) = min(m.at(i).at(j), m.at(i).at(k) + m.at(k+1).at(j) + p[i - 1] * p[k] * p[j]);
            }
        }
    }
    cout << m[1][n] << endl;
    return 0;
}

C++: /**
 * 	matrix chain multiplication
 * 	f(n,m) = multiply Mn*M(n+1)*...*M(m-1)*M(m)
 * 	f(n,n) = 1
 * 	r(n)=c(n-1)
 * 	f(n,n+1) = C(n) * R(n) * C(n+1) = c(n) * c(n-1) * c(n+1)
 * 	f(n,k,m) = f(n,k)*f(k+1,m)*C(n)*r(n)*c(k)
 * 	f(n,m) = min(f(n,k,m)
 */

#include <iostream>
#include <cmath>
#include <climits>

using namespace std;

int r[45] = {0};
int a[100][100] = {0};

int f(int n, int m);
int f(int n, int k, int m);


int f(int n, int k, int m)
{
	return f(n,k) + f(k+1,m) + (r[n] * r[k+1] * r[m+1]);
}

int f(int n, int m)
{
	if (n==m) return 0;
	int & ra = a[n][m];
	if (ra) return ra;
	ra = INT_MAX;
	for (int k=n;k<m;k++)
	{
		int ans = f(n,k,m);
		if (ans < ra) ra = ans;
	}
	return ra;
}

int main()
{
	int rr = 0;
	int cc = 0;
	int n = 0;
	cin >> n;
	for (int i=0;i<n;i++)
	{
		cin >> rr >> cc;
		r[i]=rr;
		r[i+1]=cc;
	}
	for (int i=0;i<n-1;i++)
	{
		a[i][i+1] = r[i] * r[i+1] * r[i+2];
	}
	int ans = f(0,n-1);
	cout << ans << endl;
}

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

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

typedef long long ll;

const int INF = 1 << 30;
const ll LLINF = 1LL << 62;

int mod = 1000000007;

int main(void){
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    //A*Bの行列とB*Cの行列、計A*B*C回の乗算をしてA*Cの行列になる
    int N; cin >> N;
    int R[N], C[N]; rep(i, N) cin >> R[i] >> C[i];
    int dp[N+1][N+1];
    rep(i, N+1) rep(j, N+1) dp[i][j] = INF;
    rep(i, N+1) dp[i][i+1] = 0;
    for(int haba = 2; haba <= N; haba++){
        for(int left = 0; left < N; left++){
            int right = left + haba;
            if(right > N) break;
            for(int boarder = left+1; boarder <= right-1; boarder++){
                dp[left][right] = min(dp[left][right], dp[left][boarder] + dp[boarder][right] + R[left]*C[boarder-1]*C[right-1]);
            }
        }
    }

    cout << dp[0][N] << endl;
    return 0;
}