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++: #ifdef DEBUG
#include "../utils.cpp"
#endif
#include <bits/stdc++.h>
/*
Problem


Category
DP
 
URL:


考察:



Date: 2020/06/01
*/
 

using namespace std;
using ll = int64_t;
#define int int64_t
#define INF 10e9

 
/* ==== declarations ====== */
// functions
void solve();
void getInput();
 
// global variables
int N;
vector<int> L, R;
vector<vector<int>> dp;

/* ======================== */


void getInput() {
    cin>>N;
    L = vector<int>(N, 0);
    R = vector<int>(N, 0);
    dp = vector<vector<int>>(N, vector<int>(N, 1e9));
    
    for(int i=0; i<N; ++i) {
        cin>>L[i]>>R[i];
    }
}
 

void solve() {
    
    for(int i=0; i<N; ++i) {
        dp[i][i] = 0;
    }
    for(int i=0; i+1<N; ++i) {
        dp[i][i+1] = L[i]*R[i]*R[i+1];
    }

    for(int i=2; i<N; ++i) {
        for(int j=0; i+j < N; ++j) {
            for(int k = 0; k<i; ++k) {
                int p = L[j];
                int q = R[j+k];
                int r = R[j+i];
                dp[j][j+i] = min(dp[j][j+i], p*q*r + dp[j][j+k] + dp[j+k+1][j+i]);

            }
        }
    }
    cout<<dp[0][N-1]<<endl;
}
 
 
signed main(){
    
    getInput();
    solve();
    
    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 <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 <stdio.h>
#include <iostream>
#include <vector>
#include <string>
#include <algorithm>

using namespace std;

int main(){
    int n;
    cin >> n;
    vector<int> p(n+1);
    for(int i = 0; i < n; ++i){
        cin >> p[i] >> p[i+1]; 
    }
    vector<vector<int> > dp(n, vector<int>(n));
    for(int d = 1; d < n; ++d){
        for(int i = 0; i < n - d; ++i){
            int j = i + d;
            dp[i][j] = 1 << 30;
            for(int k = i; k < j; ++k){
                dp[i][j] = min(dp[i][j], dp[i][k] + dp[k+1][j] + p[i] * p[k+1] * p[j+1]);
            }
        }
    }
    cout << dp[0][n-1] << 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 = 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;
}