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 <algorithm>
using namespace std;
#define MAX 100
#define INF 1<<30

int main(void){
  int n, p[MAX+1], m[MAX][MAX];
  cin >> n;
  for(int i=0; i<n; i++){
    cin >> p[i] >> p[i+1];
  }

  for(int i=1; i<=n; i++){
    m[i][i] = 0;
  }

  for(int l=1; l<n; l++){ // iとjの差を1からn-1まで変化させる
    for(int i=1; i<=n-l; i++){
      int j = i + l; // l-1がiとjの差
      m[i][j] = INF;
      for(int k=i; k<j; 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;
const int N = 100;
int main() {
	int n;
    int p[N + 1], a[N + 1][N + 1];
	cin >> n;
	for( int i = 0; i < n; ++i ) {
		cin >> p[i] >> p[i + 1];
	}
	for( int i = 1; i <= n; i++ ) a[i][i] = 0;

	for( int m = 2; m <= n; m++ ) { 
		for( int i = 1; i <= n - m + 1; i++ ) {
			int j = i + m - 1;
			a[i][j] = ( 1 << 21 );
			for( int k = i; k<=j - 1; k++) {
				a[i][j] = min(a[i][j], a[i][k] + a[k+1][j] + 
					p[i-1] * p[k] * p[j] );
			}
		}
	}
	cout << a[1][n] << endl;
}

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

int x[101];
int S[101][101];

int solve(int n){
  for(int i = 2; i <= n; i++){
    for ( int l = 1; l <= n - i + 1 ; l++){
      // l は 始まりの数
      int j = l + i - 1; // 終わりの数
      S[l][j] = 100000;
      for ( int k = l; k <= j-1; k++){
        S[l][j] = min(S[l][j], S[l][k] + S[k+1][j] + x[l-1]*x[k]*x[j]);
      }
    }
  }

 return S[1][n];
}

int main(){
  int n;
  cin >> n;
  int r, c;
  for ( int i = 0; i < n; i++){
    cin >> r >> c;
    if(i == 0){
      x[0] = r;
      x[1] = c;
   } else {
     x[i+1] = c;
   }
  }

  // init
  for ( int i = 0; i <= n; i++){
    S[i][i] = 0;
  }

  cout << solve(n) << endl;

  return 0;
}

C++: //http://judge.u-aizu.ac.jp/onlinejudge/description.jsp?id=ALDS1_10_B&lang=ja
//Matrix Chain Multiplication
#include <bits/stdc++.h>
#if LOCAL
#include "dump.hpp"
#else
#define dump(...)
#endif
using namespace std;
using ll=long long;
#define FOR(i,a,b) for(ll i=(a);i<(b);++i)
#define REP(i,n) FOR(i,0,n)
template<class T>bool chmax(T &a, const T &b) {if (a<b) { a=b; return 1; } return 0;}
template<class T>bool chmin(T &a, const T &b) {if (b<a) { a=b; return 1; } return 0;}
int main() {
#if LOCAL&01
	//std::ifstream in("./test/sample-1.in");
	std::ifstream in("./input.txt");
	std::cin.rdbuf(in.rdbuf());
#else
	cin.tie(0);
	ios::sync_with_stdio(false);
#endif
  ll n; cin>>n;
  vector<pair<ll,ll>> rcn(n);
  for(auto&& rc:rcn){
   cin>>rc.first>>rc.second;
  }
	vector<vector<ll>> dp(n,vector<ll>(n+1,-1));
  auto dfs = [&](auto&& self, ll l, ll r)->ll{
    if(l+1>=r)return 0;
		if(dp[l][r]>=0)return dp[l][r];
    ll ret=INT64_MAX;
    FOR(k,l+1,r){
      ll mulnum = rcn.at(l).first * rcn.at(k).first * rcn.at(r-1).second;
      chmin(ret, self(self,l,k)+self(self,k,r) + mulnum);
    }
		dump(l,r,ret);
		dp[l][r]=ret;
    return ret;
  };

	ll ans=dfs(dfs,0,n);
	cout<<ans<<endl;

  return 0;
}

C++: #include<stdio.h>
int main()
{
  int n,r[100],c[100][100];
  int i,j,k,l,m;
   
  scanf("%d",&n);
  for(i=0;i<n;i++){
    scanf("%d%d",&r[i],&j);
  }
  r[n]=j;
  for(i=1;i<=n;i++){
    c[i][i]=0;
  }
     
  for(l=2;l<=n;l++){
    for(i=1;i<=n-l+1;i++){
      j =i+l-1;
      c[i][j]=1000000;
      for(k=i;k<=j-1;k++){
    m=c[i][k]+c[k+1][j]+(r[i-1]*r[k]*r[j]);
       
    if(c[i][j]>m){
      c[i][j]=m;
    }
      }
    }
  }
  printf("%d\n",c[1][n]);
   
  return 0;
}

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

int main() {
  uint32_t n = 0;
  std::cin >> n;
  std::vector<uint32_t> mat(n + 1);
  for (uint32_t i = 0; i < n; i++) {
    std::cin >> mat[i] >> mat[i + 1];
  }

  std::vector<std::vector<uint32_t>> dp(n + 1,
                                        std::vector<uint32_t>(n + 1, -1));
  for (size_t i = 0; i < dp.size(); i++) dp[i][i] = 0;

  for (size_t d = 1; d < n; d++) {
    for (size_t i = 1; i < dp.size() - d; i++) {
      for (size_t j = 0; j < d; j++) {
        dp[i][i + d] =
            std::min(dp[i][i + d], mat[i - 1] * mat[i + j] * mat[i + d] +
                                       dp[i][i + j] + dp[i + j + 1][i + d]);
      }
    }
  }

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

  return 0;
}

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

int main(void) {
	int n, i, j, k, len;
	cin >> n;
	int p[n + 1], m[n + 1][n + 1];
	for (i = 0; i <= n; i++)
	{
		if (i == 0) {
			cin >> p[i];
		} else if (i == 1) {
			cin >> p[i];
		} else {
			cin >> p[i] >> p[i];
		}
	}

	for (i = 1; i <= n; i++) 
		m[i][i] = 0;

	for (len = 2; len <= n; len++) {
		for (i = 1; i <= n - len + 1; i++) {
			j = i + len - 1;
			m[i][j] = INT_MAX;
			for (k = i; k < j; 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;
}