Go: package main

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

type Matrix struct {
	r int // num of row
	c int // num of column
}

type Range struct {
	start int // index, inclusive
	end   int // index, inclusive
}

func (r Range) length() int {
	return r.end - r.start + 1
}

func calcMultiplication(x, y Matrix) (Matrix, int) {
	if x.c != y.r {
		panic("cannnot calculate")
	}
	return Matrix{x.r, y.c}, x.r * y.c * x.c
}

func calcMinMatrixChainMultiplication(matrices []Matrix, r Range, memo map[Range]int) (Matrix, int) {
	if v, ok := memo[r]; ok {
		return Matrix{matrices[r.start].r, matrices[r.end].c}, v
	}
	if r.length() == 0 {
		panic("must not be empty")
	} else if r.length() == 1 {
		return matrices[r.start], 0
	}

	var minCount int = math.MaxInt32

	for i := 0; i < r.length()-1; i++ {
		formerRange := Range{r.start, r.start + i}
		latterRange := Range{r.start + i + 1, r.end}
		matF, countF := calcMinMatrixChainMultiplication(matrices, formerRange, memo)
		matL, countL := calcMinMatrixChainMultiplication(matrices, latterRange, memo)
		_, countFL := calcMultiplication(matF, matL)
		count := countF + countL + countFL
		if count < minCount {
			minCount = count
		}
	}
	memo[r] = minCount
	return Matrix{matrices[r.start].r, matrices[r.end].c}, minCount
}

func main() {
	sc := bufio.NewScanner(os.Stdin)
	sc.Split(bufio.ScanWords)
	n, _ := nextInt(sc)
	matrices := make([]Matrix, n)
	for i := 0; i < n; i++ {
		r, _ := nextInt(sc)
		c, _ := nextInt(sc)
		matrices[i] = Matrix{r, c}
	}
	memo := make(map[Range]int)
	_, resultCount := calcMinMatrixChainMultiplication(matrices, Range{0, len(matrices) - 1}, memo)
	fmt.Println(resultCount)
}

func nextInt(sc *bufio.Scanner) (int, error) {
	sc.Scan()
	return strconv.Atoi(sc.Text())
}

C++: #include <iostream>
#include <cstdlib>
#include <climits>

/*
 * http://ttrsq.exblog.jp/24318687/
 */

const int MAX_N = 100;
int DP[MAX_N + 1][MAX_N + 1] = {0};
int *p;

int best(int r, int c) {
  int min = INT_MAX;
  int num = c - r;

  for (int i = 0; i < num; i++) {
    min = std::min(min, DP[r][r + i] + DP[r + i + 1][c] + p[r - 1] * p[r + i] * p[c]);
  }
  
  return min;
}

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

  int n = 0;
  std::cin >> n;
  
  p = (int *) std::malloc(sizeof(int) * n + 1);

  int bb = 0;

  std::cin >> p[0];
  std::cin >> p[1];
  
  for (int i = 2; i <= n; i++) {
    std::cin >> bb;
    std::cin >> p[i];
  }

  if (n == 1) {
    std::cout << "0" << std::endl;
  }  

  for (int i = 1; i < n; i++) {
    DP[i][i + 1] = p[i - 1] * p[i] * p[i + 1];
  }

  for (int j = 0; j <= n - 3; j++) {
    for (int i = j + 3; i <= n; i++) {
      DP[i - 2 - j][i] = best(i - 2 - j, i);
    }
  }

  std::cout << DP[1][n] << std::endl;

  return 0;
}

C++: #include <bits/stdc++.h>
typedef long long ll;
using namespace std;
#define repr(i,a,b) for(int i=a;i<b;i++)
#define rep(i,n) for(int i=0;i<n;i++)
#define invrepr(i,a,b) for(int i=b-1;i>=a;i--)
#define invrep(i,n) invrepr(i,0,n)
#define repitr(itr,a) for(auto itr=a.begin();itr!=a.end();++itr)
const int MOD=1e9+7;


int main() {
    ios_base::sync_with_stdio(false);

    int n;
    cin >> n;
    vector<int> a(n),b(n);
    rep(i,n) cin >> a[i] >> b[i];
    vector<vector<int>> dp(n,vector<int>(n,1e9)); 
    rep(i,n) dp[i][i]=0;
    repr(i,1,n) {
        invrep(j,i) {
            repr(k,j,i) {
                dp[j][i]=min(dp[j][i],dp[j][k]+dp[k+1][i]+a[j]*b[k]*b[i]);
            }
        }
    }
    cout << dp[0][n-1] << 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-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]);
		}
	}
}

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

	return 0;
}

C++: #include <bits/stdc++.h>
using namespace std;
#define rep(i, n) for(int i = 0, i##_len = (n); i < i##_len; ++i)
#define rep2(i, x, n) for(int i = x, i##_len = (n); i < i##_len; ++i)
#define all(n) begin(n), end(n)
using ll = long long;
using P = pair<int, int>;
using vi = vector<int>;
using vl = vector<ll>;
using vs = vector<string>;
using vc = vector<char>;
using vb = vector<bool>;
using vd = vector<double>;
vi dir = {-1, 0, 1, 0, -1, -1, 1, 1, -1};

int main() {
  int n;
  cin >> n;
  vi a;
  rep(i, n) {
    int b, c;
    cin >> b >> c;
    a.push_back(b);
    if(i == n - 1) a.push_back(c);
  }
  vector<vi> dp(n + 1, vi(n + 1, 1e9));
  rep(w, n + 1) {
    rep(l, n + 1 - w) {
      int r = l + w;
      if(w <= 1)
        dp[l][r] = 0;
      else if(w == 2)
        dp[l][r] = a[l] * a[l + 1] * a[r];
      else
        rep2(k, l + 1, r) dp[l][r] =
            min(dp[l][r], dp[l][k] + dp[k][r] + a[l] * a[k] * a[r]);
    }
  }
  cout << dp[0][n] << endl;
}

C++: #ifdef LOCAL_BUILD
#include "pch.h"
#define DLOG(msg) cout << "#" << __LINE__ << ":" << msg << endl;
#define DLOG_V(var)\
  cout << "#" << __LINE__ << ":" << #var << " : " << var << endl;
#else
#include <bits/stdc++.h>
#define DLOG(msg)
#define DLOG_V(var)
#endif
using namespace std;

constexpr auto no_value = numeric_limits<uint64_t>::max();

uint64_t solve(const vector<pair<int, int>>& mat) {
  auto n = mat.size();
  vector<vector<uint64_t>> cache(n - 1, vector<uint64_t>(n, no_value));
  for (size_t range = 2; range <= n; ++range) {
    for (size_t first = 0; ; ++first) {
      auto last = first + range - 1;
      if (last == n) {
        break;
      }
      for (size_t mid = first; mid != last; ++mid) {
        auto lhs = first == mid ? 0 : cache[first][mid];
        auto rhs = (mid + 1) == last ? 0 : cache[mid + 1][last];
        auto mul = mat[first].first * mat[last].second * mat[mid].second;
        cache[first][last] = min(cache[first][last], lhs + rhs + mul);
      }
    }
  }
  return cache[0][n - 1];
}

int main() {
  int n;
  cin >> n;
  vector<pair<int, int>> mat;
  for (int i = 0; i < n; ++i) {
    int row, col;
    cin >> row >> col;
    mat.push_back(make_pair(row, col));
  }
  uint64_t result = solve(mat);
  cout << result << endl;
}

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

#define INF 100000001

using namespace std;

int DP[101][101];
int *p;

int rec(int r, int c){
    int Min = INF;
    int num = c-r;

    for(int i=0; i<num; i++){
        Min = min(Min, DP[r][r+i] + DP[r+i+1][c] + p[r-1]*p[r+i]*p[c]);
    }

    return Min;
}

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

    for(int i=1; i<=N; i++) DP[i][i] = 0;

    p = (int *)malloc(sizeof(int)* (N+1));

    cin >> p[0];
    cin >> p[1];

    int bb;
    for(int i=2; i<=N; i++){
        cin >> bb;
        cin >> p[i];
    }

    for(int i=1; i<N; i++) DP[i][i+1] = p[i-1]*p[i]*p[i+1];

    for(int j=0; j<=N-3; j++){
        for(int i=3+j; i<=N; i++){
            DP[i-2-j][i] = rec(i-2-j, i);
        }
    }

    cout << DP[1][N] << endl;

    return 0;
}

C++: #include<stdio.h>
#include<algorithm>
using namespace std;

static const int N = 100;

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