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>
using namespace std;

static const int N=100;

int main()
{
    int n;
    int 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>

#define rep(i,n) for(int i = 0; i < (n); i++)
#define rrep(i,n) for(int i = (n)-1; i >= 0; i--)
#define rep1(i,n) for(int i = 1; i <= (n); i++)
#define rrep1(i,n) for(int i = (n); i > 0; i--)

#define ll long long
#define pi pair<int, int>
#define pll pair<ll, ll>

#define MOD 1000000007
#define INF 1000000000

using namespace std;

#define MAXN 101
int dp[MAXN][MAXN];

int main(){
  int n;cin>>n;
  vector<int> r(n),c(n), rc(n+1);
  rep(i, n){
    cin>>r[i]>>c[i];
    rc[i]=r[i];
  }
  rc[n]=c[n-1];
  n++;

  // rep(i, n)cout<<rc[i]<<' ';cout<<endl;
  // rep(i, n-1)cout<<r[i]<<' ';cout<<endl;
  // rep(i, n-1)cout<<c[i]<<' ';cout<<endl<<endl;

  // 行列数2について予め計算しておく
  rep(i, n-2)dp[i][i+2]=rc[i]*rc[i+1]*rc[i+2];

  // rep(i, n){rep(j, n)cout<<dp[i][j]<<' ';cout<<endl;}
  // cout<<endl;

  // 計算対象となる行列の数
  for(int len=3; len<=n; len++){
    // 行列の個数が入る分だけ左端から全て計算する
    rep(i, n-len+1){
      int j=i+len;
      dp[i][j]=INF;
      // lenの中で最後に計算する場所についてループを回して全チェック
      // 両端を含む必要はないのでkはi+1で初期化し、i+len-1までのループにする。
      for(int k=i+1; k<j; k++){
        dp[i][j] = min(dp[i][j], dp[i][k] + dp[k][j] + rc[i]*rc[j]*rc[k]);
        // cout<<i<<' '<<k<<' '<<j<<'|'<<dp[i][k]<<' '<<dp[k][j]<<' '<<rc[i]*rc[j]*rc[k]<<endl;
      }

      // rep(i, n){rep(j, n)cout<<dp[i][j]<<' ';cout<<endl;}cout<<endl;

      // cout<<endl;
    }
  }

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

  // rep(i, n){rep(j, n)cout<<dp[i][j]<<' ';cout<<endl;}
  // cout<<endl;

  return 0;
}

C++: #include <bits/stdc++.h>
#define rep(i,a,b) for(int i=int(a);i<int(b);++i)
#define SIZE 200005
#define INF 1000000005LL
//#define INF 1e18
#define MOD 1000000007

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

int n;
ll p[105];
ll dp[105][105];

int main(){

  cin >> n;
  rep(i,0,n){
    cin >> p[i] >> p[i+1];
  }

  fill(dp[0],dp[105],INF);
  rep(i,0,104){
    dp[i][i+1] = 0;
  }

  rep(k,2,n+1) rep(i,1,n+1){
    int j = i+k;
    if(j>=n+2)continue;
    rep(l,i,j-1) {
      dp[i][j] = min(dp[i][j],dp[i][l+1] + dp[l+1][j] + p[i-1]*p[l]*p[j-1]);
      //cout << i<<j<<k<<l << " " << dp[i][j] << endl;
    }
  }

  cout << dp[1][n+1] << endl;

  return 0;
}

C++: #include <iostream>
#include <string>
#include <algorithm>
#include <functional>
#include <vector>
#include <utility>
#include <cstring>
#include <iomanip>
#include <numeric>
#include <cmath>
#include <queue>
using namespace std;
typedef long long ll;
const int INF = 1<<30; 
const int MOD = 1e9 + 7;
const int dx[] = {1, 0, -1, 0};
const int dy[] = {0, 1, 0, -1};
int main()
{
    cin.tie(0);
    ios::sync_with_stdio(false);
    int n;
    cin >> n;
    int rc[110];
    for(int i = 1; i <= n; i++) cin >> rc[i - 1] >> rc[i];
    int dp[110][110];
    for(int i = 0; i < 110; i++) for(int j = 0; j < 110; j++) dp[i][j] = INF;
    for(int i = 1; i <= n; i++) dp[i][i] = 0;
    for(int alpha = 2; alpha <= n; alpha++)
    {
        for(int l = 1; l <= n - alpha + 1; l++)
        {
            int r = l + alpha - 1;
            for(int k = l; k <= r; k++)
            {
                dp[l][r] = min(dp[l][r], dp[l][k] + dp[k + 1][r] + rc[l - 1] * rc[k] * rc[r]);
            }
        }
    }
    cout << dp[1][n] << 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=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 <iostream>
#include <climits>
#define MAX 101
#define INF LLONG_MAX
using namespace std;

//the minimum matrix chain multiplication of M_i...M_j
long long m[MAX][MAX];
//M_i is p[i-1]*p[i]
long long p[MAX];

int main(){
  int n; cin >> n;
  cin >> p[0];
  for(int i=1;i<=n-1;i++){
    cin >> p[i];
    int x; cin >> x;
  }
  cin >> p[n];
  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]=INF;
      //find the minimum of M_i...M_j
      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;
}