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<stdio.h>
#include<stdlib.h>
#include<limits.h>
#define N 101

int main(){
  int a[N],b[N][N];
  int i,n,k,j,l=0,tmp=0;

  scanf("%d",&n);

  for(i=1;i<=n;i++){
    scanf("%d%d",&a[i-1],&a[i]);
  }

  for(i=1;i<=n;i++){
    b[i][i]=0;
  }
  for(j=2;j<=n;j++){
    for(i=1;i<=n-j+1;i++){
      k=i+j-1;
      b[i][k]=INT_MAX;
      for(l=i;l<=k-1;l++){
        tmp=b[i][l]+b[l+1][k]+a[i-1]*a[l]*a[k];

    if(b[i][k]>tmp){
      b[i][k]=tmp;
    }else{
      b[i][k]=b[i][k];
    }
      }
    }
  }
  printf("%d\n",b[1][n]);
  return 0;
}

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

#define MAX (1 << 21)
const int N = 1000;

int main() {
    int n;
    int m[N + 1][N + 1];
    int p[N + 1];
    for (int i = 1; i <= N; i++)
        m[i][i] = 0;
    cin >> n;
    for (int i = 0; i < n; i++) {
        cin >> p[i] >> p[i + 1];
    }
    for (int i = 2; i <= n; i++) {
        for (int j = 1; j <= n - i + 1; j++) {
            int k = j + i - 1;
            m[j][k] = MAX;
            for (int l = j; l < k; l++) {
                m[j][k] = min(m[j][k], m[j][l] + m[l + 1][k] + p[j - 1] * p[l] * p[k]);
            }
        }
    }
    cout << m[1][n] << endl;
    return 0;
}

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

signed main(){
    // cout << fixed << setprecision(10) << flush;

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

    // 最後の行列をどうやって掛けるか
    // (i-1)個 * 1個, (i-2) * (1 * 1), (i-3) * (2 * 1), ..., 1 * ((i-2) * 1)
    // のうちから最小を求め、ストックする
    // 0 <= i <= n
    // つまり、左から i 番目から j 番目までかけたときの最小の乗算の数、をストックしておく必要がある
    // dp[i][i] = 0
    // dp[i][j] = min_{i<=i_j<j} ((i ~ i_j までまとめたときの最小値) + r[i]*c[i_j]*c[j] + (i_j+1 ~ j-1 までまとめたときの最小値 + r[i_j+1]*c[j-1]*r[j]))
    // dp[i][j] = min_{i<=i_j<j} (dp[i][i_j] + r[i]*r[i_j]*c[j] + (dp[i_j+1][j-1] + r[i_j]*r[j]*c[j]))
    int INF = 1<<30;
    INF = INF<<30;
    vector<vector<int>> dp(n, vector<int>(n, INF));
    for(int i=0; i<n; i++){
        for(int j=0; j<=i; j++){
            dp[i][j] = 0;
        }
    }
    for(int i=n-1; i>=0; i--){
        for(int j=i+1; j<n; j++){
            dp[i][j] = dp[i][j-1] + r[i]*r[j]*c[j];
            for(int i_j=i; i_j<j; i_j++){
                dp[i][j] = min(dp[i][j], dp[i][i_j] + r[i]*r[i_j+1]*c[j] + (dp[i_j+1][j-1] + r[i_j+1]*r[j]*c[j]));
            }
        }
    }
    cout << dp[0][n-1] << endl;
    return 0;
}

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

int main(){
	int n;
	std::vector< int > r, c;
	std::vector< std::vector< int > > dp;
	
	std::cin >> n;
	r.resize(n);
	c.resize(n);
	dp.resize(n);
	
	for(int i=0; i<n; ++i){
		std::cin  >> r[i] >> c[i];
		dp[i].resize(n);
		dp[i][i] = 0;
	}
	
	for(int m=1; m<n; ++m){
		for(int i=0; i<n; ++i){
			int j = m + i;
			if(j>=n)break;
			
			int min = -1;
			for(int k=i; k<j; ++k){
				int t = dp[i][k] + dp[k+1][j] + r[i] * c[k] * c[j];
				
				if(min == -1 || min > t){
					min = t;
				}
			}
			dp[i][j] = min;
		}
	}
	
	std::cout << dp[0][n-1] << std::endl;
	
	return 0;
}

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

int main() 
{
    int n, p[210], m[110][110];
    cin >> n;
    for (int i = 1; i <= n; ++i) 
    {
        cin >> p[i-1] >> p[i];
    }
    for (int i = 0; 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;
}