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<map>
#include<vector>
#include<algorithm>
#include<cmath>
#include<climits>
#include<ctime>
#include<cstring>
#include<stack>
#include<queue>
#include<sstream>
#include<string>
#include<set>
#include<array>
#include<cassert>

#define ALL(v) (v).begin(),(v).end()
#define REP(i,p,n) for(int i=p;i<(int)(n);++i)
#define rep(i,n) REP(i,0,n)
#define DUMP(list) cout << "{ "; for(auto nth : list){ cout << nth << " "; } cout << "}" << endl
#define FOR(i,c) for(__typeof((c).begin())i=(c).begin();i!=(c).end();++i);

using namespace std;

const int MAX=101;
const int INF=1<<29;

int dp[MAX][MAX];
int n;
int c[MAX];
int r[MAX];

int main(){

	fill_n((int *)dp,sizeof(dp)/sizeof(int),INF);
	fill_n((int *)r,sizeof(r)/sizeof(int),0);
	fill_n((int *)c,sizeof(c)/sizeof(int),0);

	cin >> n;

	rep(i,n){
		cin >> r[i] >> c[i];	
	}

	rep(i,n){
		dp[i][i+1] = 0;
	}

	for(int R=2;R<=n;R++){
		for(int L=0;L+R-1<n;L++){
			for(int M=L+1;M<=L+R-1;M++){
				dp[L][L+R] = min(dp[L][L+R],dp[L][M] + dp[M][L+R] + (r[L] * c[M-1] * c[L+R-1]));
			}
		}
	}

	cout << dp[0][n] << endl;

}

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[i][j] << endl;
			}
		}
	}

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

	return 0;
}

C++: #include<stdio.h>
#include<stdlib.h>
#include<math.h>
int main() {
  int i, j, n, k, m[101], dp[101][101], s, t;
  
  scanf("%d", &n);
  for (i=0; i<n*2; i++)
    scanf("%d", &m[i]);  

  for (i=0; i<n; i++)
    for (j=0; j<n; j++)
      dp[i][j]=0;
 
  for (k=2; k<n; k++) {
    for (i=1; i<n-k+1; i++) {
     j=i+k-1;
     for (s=i; s<i; s++)
       dp[i][j]=m[s]*dp[i][j];
     for(t=0; t<j-1; t++)
       dp[i][j]=min(dp[i][j], dp[i][k]+dp[k+1][j]+m[i-1]*m[t]*m[j]);
    }
  }
  printf("%d",dp[1][n]);
  
  return 0;
}

C++: #include <iostream>
#include <vector>
#define rep(i, n) for(int i = 0; i < n; i++)
#define rep2(i, s, n) for(int i = s; i < n; i++)
using namespace std;

vector<int> r(100), c(100);
vector<vector<int>> dp(100, vector<int>(100, -1));
int rec(int left, int right){
  if (right - left == 0) return 0;
  if (right - left == 1) return r[left] * r[right] * c[right];
  if (dp[left][right] != -1) return dp[left][right];
  int min;
  rep2(mid, left, right){
    min = rec(left, mid) + rec(mid+1, right) + r[left] * c[mid] * c[right];
    if (dp[left][right] == -1 || dp[left][right] > min) dp[left][right] = min;
  }
  return dp[left][right];
}

int main(){
  int n;
  cin >> n;
  rep(i, n) cin >> r[i] >> c[i];
  int ans = rec(0, n-1);
  cout << ans << endl;
  return 0;
}

C++: #include <iostream>
#include <algorithm>
using namespace std;
static const int INFTY = (1 << 21);

int main() {
    int n;
    cin >> n;
    int p[n + 1], m[n + 1][n + 1];
    for (int i = 1; i <= n; i++) {
        cin >> p[i - 1] >> p[n];
        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] = INFTY;
            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 <algorithm>
#include <cstdio>
#include <iostream>

using namespace std;

int main() {
	int INFTY = 1000000000;

	int n;
	scanf("%d", &n);

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

	int m[n + 1][n + 1];

	for (int i = 1; i <= n; ++i) {
		for (int j = 1; j <= n; ++j) {
			m[i][j] = 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] = INFTY;
			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 << i << ":" << j << "," << m[i][j] << endl;
			}
		}
	}
	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 = 0;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 <iostream>
#include <vector>
#define eol '\n'
using namespace std;

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

  int n;
  cin >> n;

  vector< vector<int> > mat(n, vector<int>(n, (1 << 21)));
  vector<int> r(n), c(n);
  
  for (int i = 0; i < n; i++) {
    mat[i][i] = 0;
    cin >> r[i] >> c[i];
  }
  
  for (int l = 1; l < n; l++) {
    for (int i = 0; i < n - l; i++) {
      int j = i + l;
      for (int k = i; k < j; k++) {
        mat[i][j] = min(mat[i][j], mat[i][k] + mat[k+1][j] + r[i] * c[k] * c[j]);
      }
    }
  }

  cout << mat[0][n-1] << eol;
  return 0;
}

C++: #include <bits/stdc++.h>
using namespace std;
#define rep(i, n) for(int i=0; i<(n); i++)
#define MAX 100
int main() {

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

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

    for(int l=2; l<=n; l++){
        for(int i=1; i<=n-l+1; i++){
            int j = i + l - 1;
            m[i][j] = INT_MAX;     //INFいれる
            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;
}