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<algorithm>
using namespace std;

#define MAX_N 10000
#define INF 10000000000000000000LL

long long n, j, x[MAX_N][MAX_N], p[MAX_N + 2];

int matrix() {
	for (int i = 0; i < n; i++) { x[i][i] = 0; }
	for (int h = 2; h <= n; h++) {
		for (int i = 1; i <= n; i++) {
			j = i + h - 1;
			x[i][j] = INF;
			for (int k = i; k < j; k++) {
				x[i][k] = min(x[i][k], x[k + 1][j] + p[i - 1] * p[k] * p[j]);
			}
		}
	}
	return x[1][n];
}

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

C++: #include <iostream>

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



	int dp[n][n];

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

	int p[n + 1];

	for ( int i = 0; i < n; i++) {
		cin >> p[i] >> p[i+1];
	}


	// |--**+-|

	// |+*---| l = 2, i = 0, j=0 : p(0) * P(1) * P (2)
	// |-+*--| l = 2, i = 1, j = 1 : p(1) * p(2) * p (3); p (i) * p(j+1) * p(i+l+1)
	// |---+*| l = 2, i = 1, j = 2
	// |-++*-| l = 3, i = 1, j = 3 : p(1) * p(3) * p(4)
	// |-****| 

	// 1 2 3   1 * 2 * 3

	for (int l = 2; l <= n; l++) {
		for (int i = 0; i < n - l + 1; i++) {
			int min = INT_MAX;
			for (int j = i; j < i + l - 1;j++ ) {
				int t = dp[i][j] + p[i] * p[j + 1] * p[i + l] + dp[j+1][i + l - 1];
				if (t < min) {
					min = t;
				}
			}
			dp[i][i + l - 1] = min;
			//cout << "i:" << i << " j:" << i + l - 1 << " max:" << min << endl;
		}
	}

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

C++: /**Function Template**/
#include<bits/stdc++.h>
using namespace std;
typedef long long int ll;
typedef pair<ll,ll> pint;
const int MAX = 510000;
const int MOD = 1000000007;
#define rep(i, n) for(ll i = 0; i < (n); i++)
#define Rep(i, n) for(ll i = 1; i < (n); i++)
#define ALL(a)  (a).begin(),(a).end()
#define IOS ios::sync_with_stdio(0); cin.tie(0); cout.tie(0);
#define PI 3.14159265358979323846
#define ifYN(x) cout<<(x?"Yes":"No")<<"\n" 
ll fac[MAX], finv[MAX], inv[MAX];


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

bool palindrome(string s){
  bool flag=true;
  rep(i,s.size()) if(s[i]!=s[s.size()-1-i]) flag=false;
  return flag;
}

// テーブルを作る前処理
void COMinit() {
    fac[0] = fac[1] = 1;
    finv[0] = finv[1] = 1;
    inv[1] = 1;
    for (ll i = 2; i < MAX; i++){
        fac[i] = fac[i - 1] * i % MOD;
        inv[i] = MOD - inv[MOD%i] * (MOD / i) % MOD;
        finv[i] = finv[i - 1] * inv[i] % MOD;
    }

}
ll Len(ll n) {
  ll s=0;
  while(n!=0) s++, n/=10;
  return s;
}


ll Sint(ll n) {
  ll m=0,s=0,a=n;
  while(a!=0) s++, a/=10;
  for(ll i=s-1;i>=0;i--) m+=n/((ll)pow(10,i))-(n/((ll)pow(10,i+1)))*10;
  return m;
}


ll Svec(vector<ll> v){
  ll n=0;
  for(ll i=0;i<v.size();i++) n+=v[i];
  return n;
}


ll GCD(ll a,ll b) {
  return b ? GCD(b,a%b) : a;
}


ll LCM(ll a,ll b){
  return a/GCD(a,b)*b;
}


ll Factorial(ll n){
  ll m=1;
  while(n>=1) m*=n,n--;
  return m;
}

void runlength(string s,vector<pair<char,ll>> &p){
  ll x=1;
  if(s.size()==1){
    p.push_back(pair<char,ll>(s[0],1));
  }
  for(ll i=0;i<s.size()-1;i++){
    if(s[i]==s[i+1]){
      x++;
      if(i==s.size()-2){
        p.push_back(pair<char,ll>(s[i],x));
      }
    }else{
      p.push_back(pair<char,ll>(s[i],x));
      x=1;
      if(i==s.size()-2){
        p.push_back(pair<char,ll>(s[s.size()-1],x));
      }
    }
  }
}

ll COM(ll n,ll k){
    if (n < k) return 0;
    if (n < 0 || k < 0) return 0;
    return fac[n] * (finv[k] * finv[n - k] % MOD) % MOD;
}

ll modpow(ll a, ll n, ll mod) {
    ll res = 1;
    while (n > 0) {
        if (n & 1) res = res * a % mod;
        a = a * a % mod;
        n >>= 1;
    }
    return res;
}

string Toupper(string s){
  string ans="";
  rep(i,s.size()){
    if('a'<=s[i] && s[i]<='z') ans+=(char)s[i]-32;
    else ans+=s[i];
  }
  return ans;
}
string Tolower(string s){
  string ans="";
  rep(i,s.size()){
    if('A'<=s[i] && s[i]<='Z') ans+=(char)s[i]+32;
    else ans+=s[i];
  }
  return ans;
}


const int MAX_N=100010;
vector<bool> sieve_of_eratosthenes(){
  vector<bool> isPrime(MAX_N+1,true);
  /* isPrime[1]=false; */
  for(int i=2;i<=MAX_N;i++){
    if(isPrime[i]){
      for(int j=2*i;j<=MAX_N;j+=i){
        isPrime[j]=false;
      }
    }
  }
  return isPrime;
}

vector<pint> prime_factorize(ll n){
  vector<pint> ans;
  for(ll p=2;p<=sqrt(n);p++){
    if(n%p!=0) continue;
    ll cnt=0;
    while(n%p==0){
      n/=p;
      cnt++;
    }
    ans.push_back(make_pair(p,cnt));
  }
  if(n!=1) ans.push_back(make_pair(n,1));
  return ans;
}

/*bool cmp(pint a, pint b) { return a.second < b.second; }*/

/*↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓*/
int main() {
  IOS;
  ll n;
  cin>>n;
  vector<ll> r(n),c(n);
  rep(i,n) cin>>r[i]>>c[i];
  ll dp[n][n];
  rep(i,n) rep(j,n){
    if(i==j) dp[i][j]=0;
    else dp[i][j]=1e16;
  }
  Rep(width,n) rep(i,n-width) for(ll j=i;j<i+width;j++){
    ll num=r[i]*c[j]*c[i+width];
    chmin(dp[i][i+width],dp[i][j]+dp[j+1][i+width]+num);
  }
  cout<<dp[0][n-1]<<endl;
}

C++: #include <algorithm>
#include <bitset>
#include <cctype>
#include <climits>
#include <cmath>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <ctime>
#include <deque>
#include <functional>
#include <iomanip>
#include <iostream>
#include <list>
#include <map>
#include <numeric>
#include <queue>
#include <set>
#include <sstream>
#include <stack>
#include <string>
#include <utility>
#include <vector>
using namespace std;

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

    vector<vector<int>> dp(n + 1, vector<int>(n + 1, 1 << 25));
    for (int i = 0; i <= n; i++) {
        dp[i][i] = 0;
    }

    for (int j = 1; j < n; j++) {
        for (int i = 0; i <= n - j; i++) {
            for (int k = i + 1; k <= i + j; k++) {
                dp[i][i + j] = min(dp[i][i + j], dp[i][k - 1] + dp[k][i + j] + rs[i] * rs[k] * rs[i + j + 1]);
            }
        }
    }
    cout << dp[0][n - 1] << endl;
}