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<bits/stdc++.h>
#define rep(i, n) for (int i = 0; i < (n); ++i) 
#define PI acos(-1)

using namespace std;
using ll = long long;
using P = pair<int, int>;
using LP = pair<ll, ll>;

template<class T> inline bool chmax(T& a, T b) {if (a < b) { a = b; return true; } return false; }
template<class T> inline bool chmin(T& a, T b) {if (a > b) { a = b; return true; } return false; }

ll dpRec(int l, int r, vector<vector<ll>>& dp, vector<LP> rc) {
    if (dp[l][r] != INT_MAX) return dp[l][r];
    if (r - l == 1) {
        dp[l][r] = 0;
        return 0;
    }
    for (int i = l + 1; i < r; ++i) {
        chmin(dp[l][r], dpRec(l, i, dp, rc) + dpRec(i, r, dp, rc) + rc[l].first * rc[i].first * rc[r - 1].second);
    }
    return dp[l][r];
}

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

    int n;
    cin>>n;
    vector<LP> rc(n);
    rep(i, n) cin>>rc[i].first>>rc[i].second;

    vector<vector<ll>> dp(n + 1, vector<ll>(n + 1, INT_MAX));
    // for (int i = 2; i < n + 1; ++i) {           // 行列をi個選ぶ
    //     for (int j = 0; j < n - i + 1; ++j) {   // j番目の行列以降から
    //         for (int k = 1; k < i; ++k) {       // j番目からk個までとそれ以降の積
    //             chmin(dp[i][j], dp[k][j] + dp[i - k][j + k] + rc[j].first * rc[j + k].first * rc[j + i].first);
    //         }
    //     }
    // }
    cout<<dpRec(0, n, dp, rc)<<endl;
}

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 j=2;j<=n;j++){
    for(int i=1;i<= n-j+1;i++){
      int l = i+j-1;
      m[i][l]=(1 << 21);
      for(int k=i;k<= l-1;k++){
	m[i][l]=min(m[i][l],m[i][k]+m[k+1][l]+p[i-1]*p[k]*p[l]);
      }
    }
  }

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

  return 0;
}

C++: #include <vector>
#include <map>
#include <set>
#include <stack>
#include <queue>
#include <algorithm>
#include <numeric>
#include <utility>
#include <sstream>
#include <iostream>
#include <iomanip>
#include <cstdio>
#include <cmath>
#include <string>
#include <cstring>
#include <complex>
#include <ctime>
#include <cstdlib>

using namespace std;

inline int to_int(string s) {int v; istringstream sin(s); sin >> v; return v;}
template<class T> inline string to_str(T x) {ostringstream sout; sout << x; return sout.str();}

typedef long long ll;
typedef pair<int, int> P;
const int INF = 1<<22;

// dp[i][j] := [i , j]??????????????????????????則???????????????????属???即????????属
// |(4*5   (5*3)  3*2)|  2*1
int main()
{
	int n, dp[128][128], r[128];
	P T[128];

	cin >> n;

	for(int i = 0; i < n; i++)
	{
		for(int j = 0; j < n; j++)
		{
		 	dp[i][j] = INF;
		}
	}
	/*
	for(int i = 0; i < n; i++)
	{
		dp[i][i] = 0;
	}
	*/
	for(int i = 0; i < n; i++)
	{
		cin >> T[i].first >> T[i].second;
		dp[i][i] = 0;
	}
	/*
	r[0] = T[0].first;
	for(int i = 0; i < n; i++)
	{
		r[i+1] = T[i].second;
	}
	*/
	/*
	for(int i = 0; i <= n; i++)
	{
		cout << r[i] << endl
	}
	*/
	/*
	for(int l = 1; l < n; l++)
	{
		for(int i = 0; i < n-l; i++)
		{ 
			int j = i + l;
			for(int k = 1; k <= l; k++)
			{
				dp[i][j] = std::min(dp[i][j], dp[i][i + k - 1] + dp[i + k][j] + T[i].first*T[i + k].first*T[j].second); //r[j]*r[k]*r[i+j+1]);
			}
		}
	}
*/
	for(int i = 1; i < n; i++)
	{
		for(int j = 0; j < n-i; j++)
		{ 
			for(int k = 1; k <= i; k++)
			{
				dp[i][j] = std::min(dp[i][j], dp[k-1][j] + dp[i-k][j+k] + T[j].first*T[j + k].first*T[j + i].second); //r[j]*r[k]*r[i+j+1]);
				printf("%3d : %3d : %3d => %3d\n", i, j, k, dp[i][j]);
				//puts("run");
			}
		}
	}

	/*
	for(int i = 0; i < n; i++)
	{
		for(int j = 0; j < n; j++)
		{
			printf("%10d ",dp[i][j]);
		}
		puts("");
	}
	*/

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

C++: #include <iostream>
#include <algorithm>
#include <cstdio>
const int N = 101;

int n;
long m[N][N], p[N+2];
int j;

int matrixChainOrder(){
  for(int i=0; i<n; i++){ m[i][i] = 0; }
  for(int l=2; l<=n; l++){
    for(int i=1; i+l-1<=n; i++){
      j = i+l-1;
      m[i][j] = 100000000;
      for(int k=i; k<j-1; k++){
        m[i][j] = std::min(m[i][j], m[i][k] + m[k+1][j] + p[i-1]*p[k]*p[j]);
      }
    }
  }
  return m[1][n];
}

int main(){
  std::cin >> n; //number of matrix

  for(int i=1; i<=n; i++){
    std::cin >> p[i-1] >> p[i];
  }
  std::cout << matrixChainOrder() << std::endl;
  return 0;
}