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;
const int dx[]={1,0,-1,0,1,-1,-1,1,0};
const int dy[]={0,1,0,-1,1,1,-1,-1,0};
const int INF = 1e9+101;
const long long LINF = 1e18;
const double EPS = 1e-8;
#define pb push_back
#define mk make_pair
#define fr first
#define sc second
#define reps(i,j,k) for(int i = (j); i < (k); ++i)
#define rep(i,j) reps(i,0,j)
#define all(a) (a).begin(),(a).end()
#define MOD 1000000007
typedef long long ll;
typedef pair<int,int> Pii;
typedef pair<ll, ll> Pll;
typedef pair<Pii,int> P;
typedef vector<int> vi;
typedef vector<ll> vll;
template<class T>
ostream& operator<<(ostream &out, const vector<T> &v){
	out << "{";
	rep(i,v.size()){
		out << v[i] <<", ";
	}
	return out << "}" << endl;
}
Pll rc[128];
ll memo[128][128];
// [left, right)
ll solve(int left, int right) {
    if(memo[left][right] != -1) return memo[left][right];
    if (right - left <= 1) {
        return memo[left][right] = 0;
    }
    ll mn = LINF;
    reps(i, left+1, right) {
        ll cost = rc[left].first*rc[i-1].second*rc[right-1].second;
        mn = min(mn, solve(left, i) + solve(i, right) + cost);
    }
    return memo[left][right] = mn;
}
int main() {
    memset(memo,-1,sizeof(memo));
    int N;
    cin >> N;
    rep(i,N){
        int r,c;
        cin >> r >> c;
        rc[i] = mk(r,c);
    }
    cout << solve(0, N) << endl;
    return 0;  
}

C++: #include <bits.stdc++.h>
#define MAX 100
using namespace std;

int M[MAX][MAX];
int P[MAX][MAX];
int main(){
  int n;
  cin >> n;
  for(i = 1; i <= n; i++){
    cin >> P[i-1] >> P[i];
  }
  Ans = matrixChainMultiplication();
  return 0;
}


int matrixChainMultiplication(){
  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] = INFINITY;
  }
  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]);
  }
  return M[i][j];
}

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

struct Mat{
	  int r,l;
};

int main(){

	  int n; cin >> n;
	  vector<Mat> Mats(n);
	  for(int i=0; i<n; i++)
			cin >> Mats[i].r >> Mats[i].l;

	  int dp[n][n] = {};
	  for(int i=0; i<n; i++)
			for(int j=0; j<n; j++)
				  if(i==j) dp[i][j] = 0;
				  else dp[i][j] = INT_MAX;

	  for(int k=1; k<n; k++){
			for(int i=0; i+k<n; i++){
				  for(int j=i; j<i+k; j++){
						int num_prod = Mats[i].r * Mats[j+1].r * Mats[i+k].l;
						dp[i][i+k] = min(dp[i][i+k], dp[i][j] + dp[j+1][i+k] + num_prod);
				  }
			}
	  }
	  
	  cout << dp[0][n-1] << endl;
	  
			
}

C++: #include <stdio.h>
#include <algorithm>

using namespace std;


int main(){
	int n,minimum,tmp;
	scanf("%d",&n);
	int table[n][n];
	int data[n][2];

	for(int i=0;i<n;i++){
		for(int k=0;k<n;k++)table[i][k] = 0;
		scanf("%d %d",&data[i][0],&data[i][1]);
	}

	for(int i=n-2;i>=0;i--){
		for(int k=0;k<=i;k++){
			if(i==n-2){
				table[n-i-1][k] = data[k][0]*data[k][1]*data[k+1][1];
		}else{
				minimum = 2147483647;
				for(int p=0;p<=n-i-2;p++){
					tmp=(table[p][k]+table[n-i-p-2][k+p+1])+(data[k][0]*data[k+p][1]*data[k+n-i-1][1]);
					minimum = min(minimum,tmp);
				}
				table[n-i-1][k] = minimum;
			}
		}
	}

	printf("%d\n",table[n-1][0]);

    return 0;
}

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

int matrixChainOrder(vector<int> &p){
  auto n = p.size() - 1;
  int mat[n + 1][n + 1];
  for(auto i = 1; i <= n; i++){
    mat[i][i] = 0;
  }

  for(auto l = 2; l <= n; l++){
    for(auto i = 1; i <= n - l + 1; i++){
      auto j = i + l - 1;
      mat[i][j] = 1000000;

      for(auto k = i; k <= j - 1; k++){
        auto q = mat[i][k] + mat[k + 1][j] + p[i - 1] * p[k] * p[j];
        if(q < mat[i][j]){
          mat[i][j] = q;
        }
      }

    }
  }


  return mat[1][n];
}

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

  vector<int> mat(n + 1);
  for(auto i = 1; i <= n; i++){
    cin >> mat[i - 1] >> mat[i];
  }

  cout << matrixChainOrder(mat) << endl;

  return 0;
}

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

struct mat {
	int r, c;
	
	mat(int rv,int cv)
		:r{ rv }, c{ cv }{}
	mat() :r{}, c{} {}
	friend auto
		operator >> (std::istream&is, mat& m)->std::istream& {
		return
			is >> m.r >> m.c;
	}
};


using ui = unsigned int;
int main() {

	/*
	for (int l{ 2 }; l < 6; ++l) {

		for (int i{ 1 }; i < 6 - l + 1; ++i) {

			int j = i + l - 1;
			std::cout << "[ i, j ] = ( " << i << ", " << j << " ) >> k:";

			for (int k = i; k < j ; ++k)
				std::cout << " " << k;
			
			std::cout << "\n";
		}
		std::cout << std::endl;
	}*/
	

	int n;
	std::cin >> n;


	using ull = unsigned long long;
	using vu_t = std::vector<ull>;
	std::vector<vu_t> tab( n+1, vu_t(n+1, 0) );

	std::vector<mat> mv(n);
	for (auto&e : mv)
		std::cin >> e;

	
//	for (int i{}; i < n - 1; ++i) {
//		tab[i][i + 1] = mv[i].r * mv[i].c * mv[i + 1].c;
	//	std::cout << tab[i][i + 1] << " ";
//	}
	//std::cout << "\n";
	

	
	
	for (int l{ 2 }; l <= n; ++l) {
		for (int i{ 1 }; i <= n - l + 1; ++i) {
			ull t = (1 << 21);
			auto j = i + l - 1;
			for (int k{ i }; k <= j-1; ++k) {

				auto tt = tab[i][k] + tab[k + 1][j];
				auto c = mv[i-1].r * mv[k-1].c * mv[j-1].c;
				//std::cout << tt + c << "\t=\t" << tt << " + " << c << "\n";
				//std::cout << i << " " << k << " " << j << "\n";
				t = std::min(tt + c, t);
			}
			tab[i][j] = t;
		}
	}


//	for (const auto& e : tab) {
//		for (const auto&ee : e) {
//			std::cout << ee << "\t";
//		}std::cout << "\n";
//	}

//	put();
	std::cout << tab[1][n] << "\n";
	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+=2) 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; 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 <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;
}