Go: package main

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

const (
	initialBufSize = 100000
	maxBufSize     = 1000000
)

var sc *bufio.Scanner

func initScanner(r io.Reader) *bufio.Scanner {
	buf := make([]byte, initialBufSize)

	sc := bufio.NewScanner(r)
	sc.Buffer(buf, maxBufSize)
	sc.Split(bufio.ScanWords) // bufio.ScanLines
	return sc
}

func main() {
	sc = initScanner(os.Stdin)
	fmt.Println(resolve(parseProblem()))
}

type matrixSize struct{ row, col int }

func calcNum(i, j matrixSize) int {
	return i.row * j.col * i.col
}

func parseProblem() (int, []matrixSize) {
	n := scanInt(sc)
	sizes := make([]matrixSize, n)
	for i := 0; i < n; i++ {
		sizes[i] = matrixSize{row: scanInt(sc), col: scanInt(sc)}
	}
	return n, sizes
}

var dp [][]int

func initDP(n int) {
	dp = make([][]int, n+1)
	for i := 0; i < len(dp); i++ {
		dp[i] = make([]int, n+1)
		for j := 0; j < len(dp[i]); j++ {
			dp[i][j] = math.MaxInt64
		}
	}
}

func resolve(n int, sizes []matrixSize) int {
	// TODO 復習
	initDP(n)
	_rec(sizes, 0, n)
	return dp[0][n]
}

func _rec(sizes []matrixSize, l, r int) int {
	if dp[l][r] != math.MaxInt64 {
		return dp[l][r]
	}
	if r-l <= 1 {
		dp[l][r] = 0
		return 0
	}
	num := math.MaxInt64
	for i := l + 1; i < r; i++ {
		v := _rec(sizes, l, i) + _rec(sizes, i, r) + calcNum(matrixSize{sizes[l].row, sizes[i].row}, matrixSize{sizes[i].row, sizes[r-1].col})
		if v < num {
			num = v
		}
	}
	dp[l][r] = num
	return dp[l][r]
}

// snip-scan-funcs
func scanInt(sc *bufio.Scanner) int {
	sc.Scan()
	i, _ := strconv.Atoi(sc.Text())
	return int(i)
}
func scanString(sc *bufio.Scanner) string {
	sc.Scan()
	return sc.Text()
}

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;
}

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

int main(){
  int n,p[101],m[101][101];
  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+1;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++: // matrix chain multiplication
#include<iostream>
#define MAX 2000000
void MatrixChainMultiplication(int*,int);
int **F;
int main(){
  int n,i,j,*matrix;
  std::cin >> n;
  matrix = new int[n+1];
  F = new int*[n+1];
  for(i=1; i<=n; i++) F[i] = new int[n+1];
  for(i=0; i<n; i++){
    std::cin >> matrix[i] >> (i != n - 1 ? j : matrix[i+1]);
  }
  MatrixChainMultiplication(matrix,n);
  std::cout << F[1][n] << "\n";
  return 0;
}

void MatrixChainMultiplication(int* p,int n){
  int i,j,k,l,q;
  for(i=1; i<=n; i++) F[i][i] = 0;
  for(l=2; l<=n; l++){
    for(i=1; i<=n-l+1; i++){
      j = i + l - 1;
      F[i][j] = MAX;
      for(k=i; k<=j-1; k++){
        q = F[i][k] + F[k+1][j] + p[i-1] * p[k] * p[j];
        F[i][j] = (F[i][j] < q ? F[i][j] : q);
      }
    }
  }
}

C++: #include<stdio.h>
#define N 100
#define INF 9999999

int m[N][N], p[N], n;

void matrixChainOrder(){

  int i, j, k, l, q;

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

int main(){

  int  a, i;

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

  matrixChainOrder();
  
  printf("%d\n", m[1][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++){
		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;
typedef long long ll;

const int INF=(1<<21);

int n;
int dp[105][105], p[105];

void matrixChainMultiplication(){
    for(int i=1; i<=n; i++) dp[i][i]=0;

    for(int l=2; l<=n; l++){
        for(int i=1; i<=n-l+1; i++){
            int j=i+l-1;
            dp[i][j]=INF;
            for(int k=i; k<=j-1; k++){
                dp[i][j]=min(dp[i][j], dp[i][k]+dp[k+1][j]+p[i-1]*p[k]*p[j]);
            }
        }
    }
}

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

    matrixChainMultiplication();

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

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

const int N=100;

int main(){
	int n;
	long m[N+1][N+1], p[N+1];
	
	scanf(" %d", &n);
	for(int i=1; i<=n; ++i)
		scanf(" %ld %ld", &p[i-1], &p[i]);
		
	for(int i=1; i<=n; ++i) m[i][i]=0;
	
	for(int s=2; s<=n; ++s){
		for(int i=1; i+s-1<=n; i++){
			int j=i+s-1;
			m[i][j]=100000000;
			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]);
			}
		}
	}
	
	printf("%ld\n", m[1][n]);
}

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

#define INF (100 * 100 * 100 * 100)

int n;
int m[110][110]; //minimum cost multiply matrixes from i to j

void matrixChainOrder(int *p){
  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] = INF;
      //search the minimun cost multiply matrixes from i to j
      for(int k = i;k <= j - 1;k++){
        int q = m[i][k] + m[k + 1][j] + p[i - 1] * p[k] * p[j];
        m[i][j] = min(m[i][j], q);
      }
    }
  }
}

int main(){
  
  int p[110];

  //input
  cin >> n;
  
  for(int i = 0;i < n;i++){
    int r, c;

    //p[0] is the number of first matrix's row
    //p[i] is the number of matrixs' column
    cin >> r >> c;
    if(i) p[i + 1] = c;
    else{
      p[0] = r;
      p[1] = c;
    }
  }
  
  matrixChainOrder(p);

  //output
  cout << m[1][n] << endl;
  
  return 0;
}