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

int n;

int m[101][101];

int p[101];


void matrix(){
  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] = 1000000;
      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]);
      }
    }
  }
}

int main(){

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

  matrix();

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



  return 0;
}

C++: #include <iostream>
#include <string>
#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>
#define rep(i, n) for(int i = 0; i < (n); i++)
using namespace std;
using ll = long long;

const int INF = 1e8;

int main() {
	int n;
	cin >> n;
	vector<int> r(n), c(n);
	rep(i, n) cin >> r[i] >> c[i];
	vector<vector<int>> dp(n + 1, vector<int>(n + 1, INF));
	rep(i, n + 1) dp[i][i] = 0;
	rep(i, n) dp[i][i + 1] = 0;
	for (int w = 2; w <= n; w++) {
		for (int i = 0; i <= n - w; i++) {
			int j = i + w;
			for (int m = i + 1; m < j; m++) {
				int t = r[i] * r[m] * c[j - 1];
				dp[i][j] = min(dp[i][j], dp[i][m] + dp[m][j] + t);
			}
		}
	}
	cout << dp[0][n] << endl;
	return 0;
}

C++: #include <iostream>
#include <string>
#include <vector>
#include <algorithm>
#include <functional>
#include<numeric>
#include<cmath>
#define REP(i, n) for(int i = 0; i < n; i++)
#define REPR(i, n) for(int i = n; i >= 0; i--)
#define FOR(i, m, n) for(int i = m; i < n; i++)
#define INF 2e9
#define ALL(v) v.begin(), v.end()
using namespace std;
typedef long long ll;
typedef pair<int,int> P;

int main(){
    //cin.tie(nullptr);
	ios_base::sync_with_stdio(false);
	//cout << fixed << setprecision(15);N;
    int N; cin >> N;
    int r[N], c[N];
    REP(i,N){
        cin >> r[i] >> c[i];
    }

    /*if(N == 2){
        cout << r[0] * c[0] * c[1] << endl;
        return 0;
    }*/

    int dp[N][N];
    REP(i,N){
        REP(j,N){
            //dp[i][j] = INF;
            if(i == j) {dp[i][j] = 0;}
            else dp[i][j] = INF;
        }
    }
    //cout << dp[3][4] << endl;

    for(int w = 1; w < N; w++){
        for(int left = 0; left + w < N; left++){
            int right = left + w;
            //int mini = INF;
            for (int k = left;k < right; k++){
                int num = r[left] * r[k+1] * c[right];
                /*if(left == 3 && right == 4) {
                    cout << num << endl;
                    //cout << r[left] << " " << r[k+1] << " " << c[right] << endl;
                } */
                dp[left][left+w] = min(dp[left][left+w], dp[left][k] + dp[k+1][right] + num);
            }
        }   
    }

    cout << dp[0][N-1] << endl;
    
}