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<cstdio>
#include<iostream>
#include<algorithm>
using namespace std;
int dp[105][105];
int p[105];
void calcu(int n)
{
  for(int i=0; i<=n; i++) dp[i][i] = 0;
  for(int num=2; num<=n; num++)// num to control the number of matrix involved in multiplication.
  {
    for(int i=1; i<=n-num+1; i++)
    {
      int j = i+num-1;
      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-1]*p[k]*p[j]);
      }
    }

  }
  printf("%d\n", dp[1][n]);
}
int main()
{
  int n;
  scanf("%d", &n);
  for(int i=1; i<=n; i++)
  {
    scanf("%d%d", &p[i-1], &p[i]);
  }
  calcu(n);

  return 0;
}

C++: #include <iostream>
#include <vector>
#define MAX 10000001
using namespace std;

int main() {
    int num;
    cin >> num;
    int array[101][101];

    for(int i=0; i<=num; i++) {
        array[i][i] = 0;
    }

    vector<int> p;
    for(int i=0; i<num; i++) {
        int row, col;
        cin >> row >> col;
        if(i==0) p.push_back(row);
        p.push_back(col);
    }

    for(int l=0; l<num; l++) {
        for(int i=0; (i+l+1)<num; i++) {
            int j=i+l+1;
            array[i][j] = MAX;
            for(int k=i+l; k>=i; k--) {
                int value = array[i][k]+array[k+1][i+l+1]+(p[i]*p[k+1]*p[i+l+2]);
                array[i][j] = min(array[i][j],value);
            }
        }
    }
    cout << array[0][num-1] << endl;
}

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

int main()
{
	int i,j,k,l,m[101][101],p[101],n;
	
	cin >> n;
	
	for(i=1;i<=n;i++) cin >> p[i-1] >> p[i];
	for(i=1;i<=n;i++) m[i][i]=0;
	for(l=2;l<=n;l++)
	{
		for(i=1;i<=n-l+1;i++)
		{
			j=i+l-1;
			m[i][j]= (1 << 21);
			for(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 <cstdio>
#include <cstdlib>
#include <cassert>
#include <string>
#include <cstring>
#include <vector>
#include <list>
#include <map>
#include <set>
#include <stack>
#include <queue>
#include <algorithm>

using namespace std;

// ---------------------
// repetition
#define FOR(i,a,b) for(int i=(a);i<(b);++i)
#define REP(i,n) FOR(i,0,n)

// debug
#define dump(x)  cerr << #x << " = " << (x) << endl;
#define debug(x) cerr << #x << " = " << (x) << " (L" << __LINE__ << ")" << " " << __FILE__ << endl;

// ---------------------
#define INF 922337203685477580
typedef long long ll;

ll dp[110][110];
ll matrix[110][2];

int main() {
  int N;
  cin >> N;

  REP(i, N) {
    cin >> matrix[i][0] >> matrix[i][1];
  }

  for (int i = 0; i < N - 1; i++) {
    dp[i][i + 1] = matrix[i][0] * matrix[i][1] * matrix[i + 1][1];
  }
  for (int i = 0; i < N; i++) {
    dp[i][i] = 0;
  }

  // cout << dp[0][1] << endl;

  for (int l = 2; l <= N; l++) {
    for (int i = 0; i < N - l + 1; i++) {
      int j = i + l - 1;

      dp[i][j] = INF;

      for (int k = i; k < j; k++) {
        dp[i][j] = min(dp[i][j], dp[i][k] + dp[k + 1][j] + matrix[k][0] * matrix[k][1] * matrix[k + 1][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=0; i<=n; i++) m[i][i] = 0;
    for (int l=2; l<=n; l++) {
        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 <cstdio>
#include <cstdlib>
#include <stack>
#include <vector>
#include <algorithm>
#include <cmath>
#include <climits>
#include <cstring>
#include <queue>
#include <string>

using namespace std;

const double PI = 3.14159265358979;


int matrix_chain_multi(int p[], int len) {	// 1 2 3 num

	int m[101][101]{};
	const int num = len - 1;
	for (int L = 2; L <= num; L++) {
		
		for (int i = 1; i <= num - L + 1; i++) {
			int j = i + L - 1;
			int minx = INT_MAX;
			for (int k = i; k < j; k++)	{
				minx = min(minx, m[i][k] + m[k + 1][j] + p[i - 1] * p[k] * p[j]);
			}
			m[i][j] = minx;
		}
	}

	return m[1][len - 1];
}

int main() {

	int n; cin >> n;
	n = n + 1;

	int* p = new int[n];		// p[i-1] hang		p[i] lie
	int hang, lie, temp;
	cin >> p[0];
	for (int i = 1; i < n; i++) {
		cin >> p[i];
		if (i != n - 1)
			cin >> temp;
	}
	cout << matrix_chain_multi(p, n) << endl;


	return 0;
}