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 <vector>
#include <algorithm>
using namespace std;

#define INF 1e9

int main(void){
  int n;
  cin >> n;

  int unwanted;
  vector<int> c(n + 1);
  cin >> c[0] >> c[1];
  for(int i = 2; i <= n; i++){ cin >> unwanted >> c[i]; }

  vector<vector<int> > dp(n, vector<int>(n + 1, INF));
  for(int i = 0; i < n; i++){ dp[i][i + 1] = 0; }

  for(int k = 2; k <= n; k++){
    for(int i = 0; i < n; i++){
      for(int j = 1; j < k; j++){
        if(i + k <= n){
          dp[i][i + k] = min(dp[i][i + k], dp[i][i + j] + dp[i + j][i + k] + c[i] * c[i + j] * c[i + k]);
        }
      }
    }
  }


  // ??????
  cout << dp[0][n] << endl;


  return 0;
}

C++: #include<algorithm>
template<class T>
int mcm(T first, T last) {
    const auto N = std::distance(first, last) - 1;
    int dp[N][N];
    std::fill(dp[0], dp[N], 1 << 28);
    for (int i = 0; i < N; ++i) dp[i][i] = 0;
    for (int L = 1; L < N; ++L)
        for (int i = 0; i < N - L; ++i) {
            int j = i + L;
            for (int k = i; k < j; ++k)
                dp[i][j] = std::min(dp[i][j], dp[i][k] + dp[k + 1][j] + first[i] * first[k + 1] * first[j + 1]);
        }
    return dp[0][N - 1];
}
#include<iostream>
#include<vector>
using namespace std;
int main() {    
    cin.tie(0);
    ios::sync_with_stdio(false);
    int n;
    cin>>n;
    vector<int> vec(n+1);
    for(int i=0;i<n;++i) cin>>vec[i]>>vec[i+1];
    cout<<mcm(vec.begin(),vec.end())<<endl;
}

C++: #include <iostream>
#include <cstring>
#include <algorithm>
#include <queue>
#include <cstdio>
#include <cstdlib>
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++: /**
 * 	matrix chain multiplication
 * 	f(n,m) = multiply Mn*M(n+1)*...*M(m-1)*M(m)
 * 	f(n,n) = 1
 * 	r(n)=c(n-1)
 * 	f(n,n+1) = C(n) * R(n) * C(n+1) = c(n) * c(n-1) * c(n+1)
 * 	f(n,k,m) = f(n,k)*f(k+1,m)*C(n)*r(n)*c(k)
 * 	f(n,m) = min(f(n,k,m)
 */

#include <iostream>
#include <cmath>
#include <climits>

using namespace std;

int r[45] = {0};
int a[100][100] = {0};

int f(int n, int m);
int f(int n, int k, int m);


int f(int n, int k, int m)
{
	return f(n,k) * f(k+1,m) + (r[n] * r[k+1] * r[m+1]);
}

int f(int n, int m)
{
	if (n==m) return 0;
	int & ra = a[n][m];
	if (ra) return ra;
	ra = INT_MAX;
	for (int k=n;k<m;k++)
	{
		int ans = f(n,k,m);
		if (ans < ra) ra = ans;
	}
	return ra;
}

int main()
{
	int rr = 0;
	int cc = 0;
	int n = 0;
	cin >> n;
	for (int i=0;i<n;i++)
	{
		cin >> rr >> cc;
		r[i]=rr;
		r[i+1]=cc;
	}
	for (int i=0;i<n-1;i++)
	{
		a[i][i+1] = r[i] * r[i+1] * r[i+2];
	}
	int ans = f(0,n-1);
	cout << ans << endl;
}

C++: #include <cmath>
#include <cstdio>
#include <cstring>
#include <cstdlib>
#include <climits>
#include <map>
#include <list>
#include <stack>
#include <queue>
#include <vector>
#include <string>
#include <sstream>
#include <fstream>
#include <iostream>
#include <algorithm>
using namespace std;

int m[128], costs[128][128];
int calc(int s, int e){
	if(s==e) return 0;
	if(costs[s][e] != INT_MAX) return costs[s][e];
	return costs[s][e] = min(m[s-1] * m[s] * m[e] + calc(s+1, e), m[s-1] * m[e-1] * m[e] + calc(s, e-1));
}

int main() {
	int n;
	scanf("%d", &n);
	
	for(int i = 0; i < n; i++){
		scanf("%d %d", &m[i], &m[i+1]);
	}
	
	for(int i = 0; i <= n; i++){
		for(int j = 0; j <= n; j++){
			costs[i][j] = INT_MAX;
		}
	}
	
	printf("%d\n", calc(1, n));
	
	return 0;
}

C++: #include<iostream>


using namespace std;

#define N 100

int memo[N+1][N+1];
int q[N+1];

int main(){
  int n,i,j,k,l,min_memo;

  cin >> n;

  for(i=1;i<=n;i++) cin >> q[i-1] >> q[i];

  for(i=1;i<=n;i++) memo[i][i] = 0;

  for(l=2;l<n+1;l++){
    for(i=1;i<=n-l+1;i++){
      j = i +l -1;
      for(k = i;k<j;k++){
if(k==i) min_memo =  memo[i][k] + memo[k+1][j] + q[i-1]*q[k]*q[j];
    else  min_memo = min(min_memo, memo[i][k] + memo[k+1][j] + q[i-1]*q[k]*q[j]);
      }
      memo[i][j] =min_memo;
    }
  }

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

  return 0;
}