Go: package main

import (
	"bufio"
	"fmt"
	"os"
	"strconv"
)

//util
var sc = bufio.NewScanner(os.Stdin)

func nextStr() string {
	sc.Scan()
	return sc.Text()
}

func nextInt() int {
	sc.Scan()
	i, e := strconv.Atoi(sc.Text())
	if e != nil {
		panic(e)
	}
	return i
}

func printList(list []int) {
	buf := bufio.NewWriter(os.Stdout)
	for _, v := range list {
		buf.Write([]byte(fmt.Sprintf(" %d", v)))
	}
	buf.Write([]byte("\n"))
	buf.Flush()
}

//solve
//単純な場合
func matrixChainMultiplication() {
	//行列が1つだけのとき
	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
			//kまでで区切る
			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])
			}
		}
	}
}

func max(a, b int) int {
	if a > b {
		return a
	} else {
		return b
	}
}

func min(a, b int) int {
	if a > b {
		return b
	} else {
		return a
	}
}

const MAX = 100

var n int
var p [MAX + 1]int

//m[i][j]: Mi * Mi+1 * ... * Mjを計算するときに必要なスカラー乗算の最小回数
var m [MAX + 1][MAX + 1]int

func main() {
	sc.Split(bufio.ScanWords)
	n = nextInt()
	for i := 1; i <= n; i++ {

		p[i-1] = nextInt() //行数
		p[i] = nextInt()   //列数
	}

	matrixChainMultiplication()
	fmt.Println(m[1][n])
}

C++: #include <iostream>
#include <string>
#include <vector>
#include <queue>
#include <map>
#include <cmath>
#include <set>
#include <algorithm>

typedef long long ll;
const ll MOD = 1e9 + 7;
const long long INF = 1LL<<60;
const double PI=3.14159265358979323846;
const int NMAX=100005;
using namespace std;

int main(){
    int n;
    cin >> n;
    vector<ll> r(n),c(n);
    for(int i = 0; i < n; i++){
        cin >> r[i] >> c[i];
    }
    ll dp[n+1][n+1];
    pair<ll,ll> rc[n+1][n+1];
    for(int i = 0; i <= n; i++){
        for(int j = 0; j <= n; j++){
            dp[i][j] = INF;
        }
    }

    for(int l = 1; l <= n; l++){
        for(int i = 0; i < n; i++){
            int j = i+l;
            if(j > n) break;
            if(i+1 == j){
                dp[i][j] = 0;
                rc[i][j] = make_pair(r[i],c[i]);
            }
            for(int mid = i; mid <= j; mid++){
                ll tmp = dp[i][j];
                dp[i][j] = min(dp[i][j], dp[i][mid]+dp[mid][j]+rc[i][mid].first*rc[mid][j].second*rc[i][mid].second);
                if(dp[i][j] != tmp){
                    rc[i][j] = make_pair(rc[i][mid].first,rc[mid][j].second);
                }
            }
        }
    }

    cout << dp[0][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] + m[k + 1][j] + p[i - 1] * p[k] * p[j]);
			}
		}
	}
	cout << m[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<bits/stdc++.h>
using namespace std;
struct matrix{
	long long x,y;
}m[110];
int n;
long long dp[110][110];
int main(){
	scanf("%d",&n);
	for(int i=1;i<=n;i++){
		scanf("%d%d",&m[i].x,&m[i].y);
	}
	for(int i=1;i<=n;i++){
		dp[i][i]=0;
	}
	for(int l=2;l<=n;l++){
		for(int i=1;i<=n-l+1;i++){
			int j=i+l-1;
			dp[i][j]=1<<20;
			for(int k=i;k<j;k++){
			    dp[i][j]=min(dp[i][j],dp[i][k]+dp[k+1][j]+m[i].x*m[k].y*m[j].y);
			}
		}
	}
	//cout<<"i: "<<i<<" j: "<<j<<" dp: "<<dp[i][j]<<endl; 
	printf("%lld\n",dp[1][n]);
	return 0;
}

C++: #include <bits/stdc++.h>
using namespace std;

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

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

	vector<vector<int>> m(n+1,vector<int>(n+1));
	const int infinity=32768*32767;

	// length=2
	for (int i=0;i<=n-(2-1);++i)
	{
		m[i][i+1]=0;
	}

	// length=3
	for (int i=0;i<=n-(3-1);++i)
	{
		m[i][i+2]=size[i]*size[i+1]*size[i+2];
	}

	// length>=4
	for (int i=4;i<=n+1;++i)
	{
		for (int j=0;j<=n-(i-1);++j)
		{
			int minimum=infinity;
			for (int k=1;k<=i-2;++k)
			{
				int sum=m[j][j+k]+m[j+k][j+i-1]+size[j]*size[j+k]*size[j+i-1];
				minimum=min(minimum,sum);
			}
			m[j][j+i-1]=minimum;
		}
	}

	cout << m[0][n] << 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 <iostream>
#include <climits>
using namespace std;

long int M[101][101];
long int a[1000];
int n;
void solve(){
  for(int i=0;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]=INT_MAX;
       	  for(int k=i;k<j;k++){
	        long int tmp = M[i][k]+M[k+1][j]+a[i-1]*a[k]*a[j];
		M[i][j] = min(M[i][j],tmp);	
	    }
	}
    }
}

int main(){ 
   cin>>n;
   int p, q;
   for(int i=0; i<n; i++){
    cin>>p>>q;
    if(i == 0){
      a[i] = p;
      a[i+1] = q;
    }else{
      a[i+1] = q;
    }
  }

//   for(int i=0;i<2*n;i++)
//	cout<<a[i]<<endl;
   solve();
// for(int i=0;i<=n;i++){
//	for(int j=0;j<=n;j++){
//	    cout<<"("<<i<<","<<j<<")"<<M[i][j]<<" ";
//	}
//	cout<<endl;
 //  }
   cout<<M[1][n]<<endl;
   return 0;
}

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

#define M_PI       3.14159265358979323846   // pi

using namespace std;
typedef long long ll;
typedef unsigned long long ull;
typedef vector<ll> VI;
typedef pair<ll, ll> P;
typedef tuple<ll, ll, ll> t3;
typedef tuple<ll, ll, ll, ll> t4;
typedef tuple<ll, ll, ll, ll, ll> t5;

#define rep(a,n) for(ll a = 0;a < n;a++)
#define repi(a,b,n) for(ll a = b;a < n;a++)

using namespace std;

static const ll INF = 1e15;


int main() {
    int n;
    cin >> n;
    vector<P> ps(n);
    rep(i, n) {
        //y,x
        cin >> ps[i].first >> ps[i].second;
    }
    vector<vector<ll>> dp(n, vector<ll>(n, INF));
    rep(i, n) {
        dp[i][i] = 0;
    }
    for (int len = 1; len < n; len++) {
        for (int left = 0; left < n-len; left++) {
            int right = left + len;
            for (int middle = left; middle < right; middle++) {
                ll add1 = ps[left].first * ps[middle].second * ps[right].second;
                ll u1 = dp[left][middle] + dp[middle+1][right] + add1;
                dp[left][right] = min(dp[left][right], u1);
            }
        }
    }
    cout << dp[0][n - 1] << endl;
    return 0;
}