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<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;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 <limits.h>
#define MAX 100

int main(){
  int n, m[MAX+1][MAX+1];
  int i, j, k, r, min;
	
  scanf("%d", &n);
  for(i=1;i<=n;++i) {
    scanf("%d %d", &m[i][i-1], &m[i+1][i]);
    m[i][i] = 0;
  }
	
  for(r=2;r<=n;++r){
    for(i=1;i<=n-r+1;++i){
      j=i+r-1;
      m[i][j] = INT_MAX;
      for(k=i;k<=j-1;++k){
	min = m[i][k]+m[k+1][j]+m[i][i-1]*m[k+1][k]*m[j+1][j];
	if(m[i][j] > min) m[i][j] = min;
      }
    }
  }
  printf("%d\n", m[1][n]);
  return 0;
}

C++: #define _CRT_SECURE_NO_WARNINGS
#define _USE_MATH_DEFINES
#include <iostream>
#include <cstdio>
#include <algorithm>
using namespace std;
const int num = 105;
int p[num];
int main() {
	int n;
	cin >> n;
	for (int i = 1; i <= n; i++) {
		scanf("%d%d", &p[i-1], &p[i]);
	}
	int m[num][num];
	for (int i = 1; i <= n; i++) {
		for (int j = 1; j <= n; j++) {
			m[i][j] = 999999999999;
		}
	}
	for (int i = 1; i <= n; i++) m[i][i] = 0;
	for (int l = 1; l < n; l++) {
		for (int i = 1; i < n - l + 1; i++) {
			int j = i + l;
			for (int k = i; k < j; 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;

constexpr 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; 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;
}

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

using namespace std;

static const int N = 100;
static int m[N + 1][N + 1] = {}, p[N + 1] = {};

static inline void matrixChainMultiplication(int n) {
  for (int l = 2; l <= n; l++) {
    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[k] * p[j]); 
      }
    }
  }
}

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

  matrixChainMultiplication(n);
  
  cout << m[1][n] << endl;

  return 0;
}

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

int main(void){
  ios::sync_with_stdio(false);
  cin.tie(0);

  int n; cin >> n;
  vector<int> p(n+1);
  cin >> p[0] >> p[1];
  for(int i = 0; i < n-2; i++){
    int a, b; cin >> a >> b;
    p[i+2] = b;
  }
  {
    int a, b; cin >> a >> b;
    p[n] = b;
  }

  int dp[101][101];
  memset(dp, 0, sizeof(dp));

  n = p.size() - 1;
  for(int l = 2; l <= n; l++){
    for(int i = 1; i <= n-l+1; i++){
      int j = i+l-1;
      dp[i][j] = INT_MAX/10;
      for(int k = i; k < j; 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;
}