Go: package main

/*
連鎖行列積
*/

import (
	"bufio"
	"bytes"
	"fmt"
	"log"
	"math"
	"os"
	"strconv"
	"strings"
)

func min(a, b int) int {
	if a < b {
		return a
	}
	return b
}

type mem *[][]int

func main() {
	scanner := makeScanner(1024)
	n := eGetInt(scanner)
	p := make([]int, n+1)
	for i := 0; i < n; i++ {
		rowcol := eGetInts(scanner)
		p[i] = rowcol[0]
		p[i+1] = rowcol[1]
	}
	m := make([][]int, n)
	for i := 0; i < n; i++ {
		m[i] = make([]int, n)
	}
	// 初期値の格納
	for i := 0; i < n; i++ {
		for j := i; j < n; j++ {
			if i == j {
				m[i][j] = 0 //  同じ行列へのコストは当然0
			} else {
				m[i][j] = math.MaxInt64
			}
		}
	}

	// num : 行列の数. num == 1の場合は初期値0を格納ずみ
	for num := 2; num <= n; num++ {
		// s : スタート行列番号
		for s := 0; s+num <= n; s++ {
			// t : 終了行列番号
			t := s + num - 1
			// k : 仕切
			for k := s; k < t; k++ {
				m[s][t] = min(m[s][t], m[s][k]+m[k+1][t]+p[s]*p[k+1]*p[t+1])
			}
		}
	}
	fmt.Println(m[0][n-1])
}

////////////////////////////////////////////////////////////////////////////////
// ライブラリ
////////////////////////////////////////////////////////////////////////////////
func makeScanner(maxByte int) *bufio.Scanner {
	scanner := bufio.NewScanner(os.Stdin)
	scanner.Buffer(make([]uint8, 0, 8192), maxByte)
	return scanner
}
func makeWordScanner() *bufio.Scanner {
	scanner := makeScanner(8192)
	scanner.Split(bufio.ScanWords)
	return scanner
}
func eGetLine(r *bufio.Scanner) string {
	if r.Scan() {
		return r.Text()
	}
	err := r.Err()
	if err != nil {
		log.Fatal(err)
	}
	// EOF
	return ""
}
func eGetInt(r *bufio.Scanner) int {
	line := eGetLine(r)
	return eAtoi(line)
}
func eGetFields(r *bufio.Scanner) []string {
	line := eGetLine(r)
	return strings.Fields(line)
}
func eGetInts(r *bufio.Scanner) []int {
	fields := eGetFields(r)
	ints := make([]int, len(fields))
	for i := 0; i < len(ints); i++ {
		ints[i] = eAtoi(fields[i])
	}
	return ints
}
func eGetChars(r *bufio.Scanner) []string {
	line := eGetLine(r)
	return strings.Split(line, "")
}
func eAtoi(s string) int {
	n, err := strconv.Atoi(s)
	if err != nil {
		log.Fatal(err)
	}
	return n
}

type ints []int

func (s ints) String() string {
	var buf bytes.Buffer
	buf.WriteString("[")
	sep := ""
	for _, v := range s {
		buf.WriteString(fmt.Sprintf("%s%d", sep, v))
		sep = ", "
	}
	buf.WriteString("]")
	return buf.String()
}

func reverse(a ints) ints {
	r := make(ints, len(a))
	for i := 0; i < len(a); i++ {
		r[i] = a[len(a)-1-i]
	}
	return r
}
func max(a ints) (int, bool) {
	if len(a) == 0 {
		return 0, false
	}
	m := a[0]
	for _, e := range a {
		if e > m {
			m = e
		}
	}
	return m, true
}

// func min(a []int) int {
// 	m := a[0]
// 	for _, v := range a {
// 		if v < m {
// 			m = v
// 		}
// 	}
// 	return m
// }

func sum(a ints) int {
	if len(a) == 0 {
		return 0
	}
	sum := 0
	for _, e := range a {
		sum += e
	}
	return sum
}
func find(n int, a ints) int {
	for i, v := range a {
		if n == v {
			return i
		}
	}
	return -1
}

C++: //============================================================================
// Name        : MatrixChainMultiplication.cpp
// Author      : Ken
// Version     :
// Copyright   : Your copyright notice
// Description : Hello World in C++, Ansi-style
//============================================================================

#include <iostream>
#include <vector>
#include <map>
using namespace std;

struct Matrix{
	int row;
	int col;
};

class MatrixList{
public:
	vector<Matrix> matrices;
	map<string, int> minProcess;
	map<string, int>::iterator p;
	MatrixList():matrices(), minProcess(){}

	void insert(const Matrix& mat){
		matrices.push_back(mat);
	}

	int calcMinProcess(int i, int j){
		if(not(i>=0 and i<j and j<=matrices.size())){
			cout << "calcMinProcess: i and j are invalid\n";
			return -1;
		}

		string key = to_string(i) + ":" + to_string(j);

		p = minProcess.find(key);
		if(p != minProcess.end()){
			return minProcess[key];
		}

		if(j == i+1){
			return 0;
		}

		int min = 100000000;

		for(int k=i+1; k<j; k++){
			int tmp = calcMinProcess(i, k) + calcMinProcess(k, j) + matrices.at(i).row * matrices.at(k-1).col * matrices.at(j-1).col;
			if(tmp < min){
				min = tmp;
			}
		}

		minProcess[key] = min;
		return min;
	}

	void writeMatList(){
		for(int i=0; i<matrices.size(); i++){
			cout << matrices.at(i).row << " " << matrices.at(i).col << "\n";
		}
	}
};

int main() {
	int n, row, col;
	cin >> n;
	MatrixList matList;

	for(int i=0; i<n; i++){
		cin >> row >> col;
		Matrix mat = {row, col};
		matList.insert(mat);
	}

	//matList.writeMatList();
	cout << matList.calcMinProcess(0, matList.matrices.size()) << "\n";

	return 0;
}

C++: #include<iostream>
#include<algorithm>
#include<vector>
#include<stdio.h>
#include<cstring>
#include<math.h>
#include<map>
#include<bitset>
#include<iomanip>
#include<queue>
using namespace std;

#define rep(i, n) for (int i = 0; i < (int)(n); ++i)

int n;
int r[100], c[100];
int dp[100][100];
const int INF = 1000000000;

int main() {
  cin >> n;
  rep(i, n) {
    cin >> r[i] >> c[i]; 
  }
  rep(i, 100) {
    rep(j, 100) {
      if(i == j) dp[i][j] = 0;
      else dp[i][j] = INF;
    }
  }

  for(int w = 1; w < n; w++) {
    for(int i = 0; i + w < n; i++) {
      int j = i + w;
      for(int k = 0; k < j; k++) {
        int num_prod = r[i] * c[k] * c[j];
        dp[i][j] = min(dp[i][j], dp[i][k] + dp[k+1][j] + num_prod);
      }
    }
  }

  cout << dp[0][n-1] << endl;
  return 0;
}

C++: #include <iostream>
#include <algorithm>
const int MAX_N = 100;
const int INF = 999999999;
using namespace std;

int dp[MAX_N+1][MAX_N+1];
int p[MAX_N+1];

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

    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]);
            }
        }
    }

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

    return 0;
}

C++: #include <iostream>
using namespace std;
int n,a[100],b[100],dp[100][100];
int main(void){
    cin>>n;
    for(int i=0;i<n;i++){
        cin>>a[i]>>b[i];
    }
    for(int i=0;i<100;i++){
        for(int j=0;j<100;j++){
            if(i!=j)dp[i][j]=1e9;
        }
    }
    for(int j=1;j<n;j++){
        for(int i=0;i+j<n;i++){
            for(int k=i;k<i+j;k++){
                dp[i][i+j]=min(dp[i][i+j],dp[i][k]+dp[k+1][i+j]+a[i]*b[i+j]*b[k]);
            }
        }
    }
    cout<<dp[0][n-1]<<endl;
}

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

const long N = 100;

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

     for ( long i = 1; i <= n; i++ )   m[i][i] = 0;
     for ( long l = 2; l <= n; l++ ) {
          for ( i = 1; i <= n - l + 1; i++ ) {
               long j = i + l - 1;
               m[i][j] = (1 << 21);
               for ( long 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;

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;
}