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 <stdio.h>
#include <string.h>
#define N 110
#define INF_MAX 0x3f3f3f3f
int p[N];
int m[N][N];
int n;
int main(){
    scanf("%d", &n);
    for(int i = 0; i < n; i++) scanf("%d %d", &p[i], &p[i+1]);
    for(int i = 0; i < n; i++) m[i][i] = 0;
    for(int len = 2; len <= n; len++){
        for(int i = 1; i <= n-len+1; i++){
            int j = i+len-1;
            m[i][j] = INF_MAX;
            for(int k = i; k < j; k++){
                int temp = m[i][k] + m[k+1][j] + p[i-1]*p[k]*p[j];
                m[i][j] = m[i][j] < temp ? m[i][j] :temp;
            }
        }
    }
    printf("%d\n", m[1][n]);
    return 0;
}

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

#define REP(i, n) for(int i = 0; i < (n); i++)
#define FOR(i, a, b) for(int i = (a); i < (b); i++)
#define INF 999999999

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

  REP(i, n) m[i][i] = 0;
  FOR(l, 2, n + 1) {
    REP(i, n - l + 1) {
      int j = i + l - 1;
      m[i][j] = INF;
      FOR(k, i, j) {
        m[i][j] = min(m[i][j], m[i][k] + m[k + 1][j] + p[i] * p[k + 1] * p[j + 1]);
      }
    }
  }
  cout << m[0][n - 1] << endl;;
  return 0;
}

C++: #include <algorithm>
#include <cstdio>
#include <iostream>
#include <map>
#include <cmath>
#include <queue>
#include <set>
#include <sstream>
#include <stack>
#include <string>
#include <vector>
#include <stdlib.h>
#include <stdio.h>
#include <bitset>
#include <cstring>
#include <deque>
#include <iomanip>
#include <limits>
#include <fstream>
using namespace std;
#define FOR(I,A,B) for(int I = (A); I < (B); ++I)
#define CLR(mat) memset(mat, 0, sizeof(mat))
typedef long long ll;
ll memo[111][111];
int n, a[111], b[111];
ll rec(int l, int r){
    if(memo[l][r] != 1e9) return memo[l][r];
    if(l == r) return memo[l][r] = 0;
    if(r - l == 1){
      return memo[l][r] = a[l]*b[l]*b[r];
    }
    ll ret = 1e9;
    FOR(m, l, r){
      ret = min(ret, rec(l, m) + rec(m + 1, r) + a[l] * b[m] * b[r]);
    }
    return memo[l][r] = ret;
}
int main()
{
  ios::sync_with_stdio(false);
  cin.tie(0);
  cin >> n;
  FOR(i,0,n) cin >> a[i] >> b[i];
  FOR(i,0,111)FOR(j,0,111)memo[i][j]=1e9;
  cout << rec(0,n-1) << endl;
}

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

struct matrix_size{
	int row;
	int col;
};

int matrixchaincost(vector <matrix_size> &M){
	int n=M.size();
	vector < vector <int> > cost(n, vector <int> (n));
	vector < vector <matrix_size> > X(n, vector <matrix_size> (n));
	for (int i=0; i<n; i++){
		cost[i][i] = 0;
		X[i][i] = M[i];
	}

	for (int length=2; length<=n; length++){
		for (int i=0; i+length<=n; i++){
			int j = i+length-1;
			X[i][j].row = X[i][i].row;
			X[i][j].col = X[j][j].col;
			if (X[i][j-1].col != X[j][j].row){
				cout<<"error"<<endl;
				return NULL;
			}
			int k = i+1;
			int mincost = X[i][k-1].row * X[i][k-1].col * X[k][j].col + cost[i][k-1] + cost[k][j];
			k++;
			while (k<=j){
				int tmp = X[i][k-1].row * X[i][k-1].col * X[k][j].col + cost[i][k-1] + cost[k][j];
				if (tmp<mincost)
					mincost = tmp;
				k++;
			};
			cost[i][j] = mincost;
		}
	}
	return cost[0][n-1];
}

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

	vector <matrix_size> M(n);

	for (int i=0; i<n; i++){
		cin>>M[i].row;
		cin>>M[i].col;
	}
	cout<<matrixchaincost(M)<<endl;
	return 0;
}

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

static const int N=100;

using namespace std;

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 <bits/stdc++.h>
using namespace std;
#define rep(i, n) for (int i = 0; i < (int)(n); i++)
#define repr(i, n) for (int i = (int)(n); i >= 0; i--)
#define REP(i, m, n) for (int i = (int)(m); i <= (int)(n); i++)
#define REPR(i, m, n) for (int i = (int)(m); i >= (int)(n); i--)
#define all(v) v.begin(), v.end()
typedef long long ll;
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 (a > b) { a = b; return 1; } return 0; }

const int INF = 1001001001;

int n;
int p[110];
int dp[110][110];

int main(){
  cin >> n;
  REP(i, 1, n) cin >> p[i-1] >> p[i];

  memset(dp, INF, sizeof(dp));
  rep(i, n+1) dp[i][i] = 0;

  REP(l, 2, n){
    REP(i, 1, n-l+1){
      int j = i+l-1;
      REP(k, i, j-1){
        chmin(dp[i][j], dp[i][k]+dp[k+1][j]+p[i-1]*p[k]*p[j]);
      }
    }
  }

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

  return 0;
}

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

int mcm(int n,int p[]){
	int m[n+1][n+1]={0};
	for(int s=0;s<n;s++){
		for(int i=1,j=s+2;j<=n;i++,j++){
			m[i][j]=1<<30;
			for(int k=i;k<j;k++){
				int tmp=m[i][k];
				tmp+=m[k+1][j];
				tmp+=p[i-1]*p[k]*p[j];
				m[i][j]=min(m[i][j],tmp);
			}
		}
	}
	return m[1][n];
}

int main(){
	int n;
	cin >> n;
	int p[n+1];
	for(int i=0;i<n;i++){
		int n1,n2;
		cin >> n1 >> n2;
		p[i]=n1;
		if(i==n-1) p[i+1]=n2;
	}
	
	cout << mcm(n,p) << endl;
	return 0;
}

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

void fnInput(vector<int>& rvnMtrx)
{
  int nMaxSiz;
  cin >> nMaxSiz;
  rvnMtrx.resize(nMaxSiz + 1);

  for (int i = 0; i < rvnMtrx.size() - 1; ++i)
    cin >> rvnMtrx[i] >> rvnMtrx[i + 1];
}

int fnMtrxChainMultpl(vector<vector<int>>& rvvnDetDP, const vector<int>& cnrvnMtrx)
{
  for (int i = 1; i < cnrvnMtrx.size(); ++i)  rvvnDetDP[i][i] = 0;

  const int cnMaxSiz = cnrvnMtrx.size() - 1;
  for (int nDif = 1; nDif <= cnMaxSiz - 1; ++nDif)
    for (int nRow = 1; nRow <= cnMaxSiz - nDif; ++nRow)
    {
      int nCol = nRow + nDif;
      for (int nx = nRow; nx <= nCol - 1; ++nx)
        rvvnDetDP[nRow][nCol] =
          min(rvvnDetDP[nRow][nCol],
              rvvnDetDP[nRow][nx] + rvvnDetDP[nx + 1][nCol] 
                                  + cnrvnMtrx[nRow - 1] * cnrvnMtrx[nx] * cnrvnMtrx[nCol]);
    }
}

int main()
{
  cin.tie(0);
  ios::sync_with_stdio(false);
  vector<vector<int>> vvnDetDP; 
  vector<int> vnMtrx;

  fnInput(vnMtrx);
  vvnDetDP.resize(vnMtrx.size(), vector<int>(vnMtrx.size(), INT_MAX));

  fnMtrxChainMultpl(vvnDetDP, vnMtrx);
  cout << vvnDetDP[1][vnMtrx.size() - 1] << endl;
  return 0;
}