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>
using namespace std;
#define MAX 200
#define INFTY (1<<21)

int m[MAX][MAX], n, p[MAX];

void matrix()
{
    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] = INFTY;
            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()
{
    cin >> n;
    for(int i=1; i<=n; i++)
        cin >> p[i-1] >> p[i];
    matrix();
    cout << m[1][n] << endl;
    return 0;
}

C++: #include<stdio.h>

static const int N = 100;

int min(int a, int b){
  return a < b ? a : b;
}

int main(){
  int N1[N+1],N2[N+1][N+1];
  int i,j,k,l,n;
 
  scanf("%d",&n);
  for(i=1;i<=n;i++){
    scanf("%d %d",&N1[i-1],&N1[i]);
  }

  for(i=1;i<=n;i++)N2[i][i] = 0;
  for(l=2;l<=n;l++){
    for(i=0;i<=n-l+1;i++){
      j = i+l-1;
      N2[i][j] = (1<<21);
      for(k = i;k <= j-1;k++){
	N2[i][j] = min(N2[i][j],N2[i][k] + N2[k+1][j] + N1[i-1]*N1[k]*N1[j]);
      }
    }
  }

  printf("%d\n",N2[1][n]);
  
  return 0;
}

C++: #include <bits/stdc++.h>

#define REP(i, s, n) for (int i = s; i < n; i++)
#define rep(i, n) REP(i, 0, n)

using namespace std;

// data
const int MAX_N = 100;
int A[MAX_N][2]; // 0-col, 1-row
enum
{
    row, col
};

// dp
int dp[MAX_N+1][MAX_N]; // k number from A_i;
const int INF = 1 << 29;

int main(){
    int n; cin >> n;
    rep(i, n){
        cin >> A[i][row] >> A[i][col];
    }

    rep(k, n+1){
        rep(i, n){
            if (k <= 1)
                dp[k][i] = 0;
            else    
                dp[k][i] = INF;
        }
    }

    rep(k, n+1){
        rep(i, n){
            rep(j, k)
                dp[k][i] = min(dp[k][i], 
                    dp[j][i] + dp[k-j][i+j] + A[i][row]*A[i+j][row]*A[i+k-1][col]);
        }
    }

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

}

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

const int N=100;

int main(){
	int n;
	long m[N+1][N+1], p[N+1];
	
	scanf(" %d", &n);
	for(int i=1; i<=n; ++i)
		scanf(" %ld %ld", &p[i-1], &p[i]);
		
	for(int i=0; i<=n; ++i) printf("p[%d]=%ld\n", i, p[i]);
		
	for(int i=1; i<=n; ++i) m[i][i]=0;
	
	for(int s=2; s<=n; ++s){ //s??????????????????
		for(int i=1; i+s-1<=n; ++i){ //?§????i
			int j=i+s-1; //??????j
			m[i][j]=100000000; //????????§???????????§?????????
			for(int k=i; k<=j-1; ++k){ //?????????k
				m[i][j]=min(m[i][j], m[i][k]+m[k+1][j]+p[i-1]*p[k]*p[j]);
				//printf("go %d %d %d\n",i, j, k);
			}
		}
	}
	
	printf("%ld\n", m[1][n]);
}

C++: // Chain matrix multiplication (DP)

#include <algorithm>
#include <iostream>
#include <limits>
#include <vector>

using namespace std;
int main() {
  int n;
  cin >> n;

  int a, b;
  vector<int> A, B;
  while (cin >> a >> b) {
    A.push_back(a);
    B.push_back(b);
  }

  int cost[n][n];
  for (int i = 0; i < n; ++i) {
    for (int j = 0; j < n; ++j) {
      cost[i][j] = 0;
    }
  }

  // len=0 => cost = 0, the default value
  for (int len = 1; len < n; ++len) {
    for (int i = 0; i < n - len; ++i) {
      int j = i + len;
      int best = numeric_limits<int>::max();
      for (int k = i; k < j; ++k) {
        best = min(best, cost[i][k] + cost[k + 1][j] + A[i] * B[k] * B[j]);
      }
      cost[i][j] = best;
    }
  }

  cout << cost[0][n - 1] << 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 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++: #include <bits/stdc++.h>
using namespace std;
#define rep(i,n) for(int (i)=0;(i)<(n);(i)++)

struct Matrix {
  int low;
  int col;
};

int main() {
  int n; cin >> n;
  vector<Matrix> l(n);
  rep(i, n) {
    int a, b; cin >> a >> b;
    l.at(i).low = a;
    l.at(i).col = b;
  }

  vector<vector<int>> dp(n, vector<int>(n));
  rep(i, n) {
    dp.at(i).at(i) = 0;
  }

  for (int j = 1; j<n; j++) {
    int i = j-1;
    while (i>=0) {
      int k = i;
      int mi = 100000000;
      while (k < j) {
        mi = min(mi, (l.at(i).low * l.at(k).col * l.at(j).col) + dp.at(i).at(k) + dp.at(k+1).at(j));
        k++;
      }
      dp.at(i).at(j) = mi;
      i--;
    }
  }
  cout << dp.at(0).at(n-1) << endl;
}