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++: // Ref : https://book.mynavi.jp/ec/products/detail/id=35408

#include <iostream>
#include <algorithm>
#include <limits.h>
using namespace std;

static const int N = 100;;

int main() {
	int n; cin >> n;
	int p[N + 1], m[N + 1][N + 1]; // m_ij is partial LCS between i to j.
	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++) { // l is a length of partial LCS.
		for (int i = 1; i <= n - l + 1; i++) {
			int j = i + l - 1;
			m[i][j] = INT_MAX;
			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[j] * p[k]);
			}
		}
	}
	cout << m[1][n] << endl;

	return 0;
}

C++: #include <iostream>

using namespace std;

static const int MAX = 100;

class MatrixChainMultiplication {
private:
    int MCM[MAX + 1][MAX + 1];
    int p[MAX + 1];
    int n;

    void set()
    {
        cin >> n;
        cin >> p[0];
        int _;
        for(int i = 1; i <= n; i++)
        {
            cin >> p[i];
            if(i == n)
                break;
            cin >> _;
        }
    }

public:
    MatrixChainMultiplication()
    {
        set();
    }

    int matrix_chain_multiplication()
    {
        for(int i = 1; i <= n; i++)
            MCM[i][i] = 0;

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

        return MCM[1][n];
    }
};

int main()
{
    MatrixChainMultiplication mcm;
    cout << mcm.matrix_chain_multiplication() << endl;
}

C++: #include <bits/stdc++.h>
using namespace std;
//using ll = long long;
#define MAX 100000000000000;

/*
int MCM(int i, int j, int p[]) {
  int min = MAX;
  if (i == j) return 0;
  if (i < j) {
    int temp;
    for (int k = i; k < j; k++) {
      temp = MCM(i, k, p)+MCM(k+1, j, p)+p[i-1]*p[k]*p[j];
      if (min > temp) min = temp;
    }
  }
  return min;
}
*/

int main(void) {
  int n; cin >> n;
  int r[n]; int c[n];
  for (int i = 0; i < n; i++) {
    cin >> r[i] >> c[i];
  }

  long long m[n+1][n+1]; int p[n+1];
  for (int i = 0; i < n; i++) p[i] = r[i]; p[n] = c[n-1];
  for (int i = 1; i <= n; i++) m[i][i] = 0;
  //int ans = MCM(1, n, p);
  //cout << ans << endl;  
  for (int k = 1; k < n; k++) { //kはm[i][j]におけるj-iの値
    for (int i = 1; i+k <= n; i++) { //iはm[i][j]におけるi
    long long temp; m[i][i+k] = MAX; //tempmin_はm[i][i+k]の値
      for (int l = i; l < i+k; l++) { //lはm[i][i+k]を分割する地点
        temp = m[i][l]+m[l+1][i+k]+p[i-1]*p[l]*p[i+k];
        if (m[i][i+k] > temp) m[i][i+k] = temp;
      }
    }
  }
  cout << m[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=0; i<=n; ++i) printf("p[%d]=%ld\n", i, p[i]);
		
	for(int i=1; i<=n; ++i) m[i][i]=0;
	
	for(int s=2; s<=n; ++s){ //s??????????????????
		for(int i=1; i+s-1<=n; ++i){ //?§????i
			int j=i+s-1; //??????j
			m[i][j]=100000000; //????????§???????????§?????????
			for(int k=i; k<=j-1; ++k){ //?????????k
				m[i][j]=min(m[i][j], m[i][k]+m[k+1][j]+p[i-1]*p[k]*p[j]);
				//printf("go %d %d %d\n",i, j, k);
			}
		}
	}
	
	printf("%ld\n", m[1][n]);
}

C++: #include<bits/stdc++.h>
#define INF 1e9

using namespace std;

int main()
{
  int n;
  int a[105];
  
  cin >> n;

  for(int i=0;i < n;i++){
    cin >> a[i] >> a[i+1];
  }
  //dp[i][j] := iからj番目の行列積に必要なスカラー積の最小値
  int dp[105][105] = {};

  //init
  for(int i=0;i < n;i++){
    for(int j=0;j < n;j++){
      if(i == j) dp[i][j] = 0;//iからiまでは当然 0回
      else dp[i][j] = INF;
    }
  }
  
  for(int m = 0; m < n ;m++){
    for(int i = 0; m+i < n ;i++){
      int j = m+i;
      for(int k = i; k < j ;k++){
	dp[i][j] = min(dp[i][j], dp[i][k] + dp[k+1][j] + a[i]*a[k+1]*a[j+1]);
      }
    }
  }
  cout << dp[0][n-1] << endl;
  return 0;
}

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

int main() {
	int n, p[101], m[101][101];
	std::cin >> n;
	for (int i = 1; i <= n; i++) {
		std::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] = std::min(m[i][j], m[i][k] + m[k + 1][j] + p[i - 1] * p[k] * p[j]);
			}
		}
	}
	std::cout << m[1][n] << std::endl;
	return 0;
}