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 <bits/stdc++.h>
using namespace std;

#define FOR(i,a,b) for(int i=(a);i<=(b);++i)
#define REP0(i,n) for(int i=0, i##_len=(n); i<i##_len; ++i)
#define REP1(i,n) for(int i=1, i##_len=(n); i<=i##_len; ++i)
#define RREP0(i,n) for(int i=n-1; i>=0; --i)
#define RREP1(i,n) for(int i=n; i>=1; --i)

#define SORT(c) sort((c).begin(),(c).end())
#define whole(f,x,...) ([&](decltype((x)) whole) { return (f)(begin(whole), end(whole), ## __VA_ARGS__); })(x)
#define PB push_back
#define MP make_pair
#define SZ(a) int((a).size())
#define EXIST(s,e) ((s).find(e)!=(s).end())
#define CLR(a) memset((a), 0 ,sizeof(a))

inline int toInt(string s) {int v; istringstream sin(s);sin>>v;return v;}
template<class T> inline string toString(T x) {ostringstream sout;sout<<x;return sout.str();}

typedef long long LL;
typedef vector<int> VI;
typedef vector<VI> VVI;
typedef vector<string> VS;
typedef pair<int, int> PII;

const int INTINF = 2147483647;
const LL LLINF = 9223372036854775807;
const double EPS = 1e-10;
const double PI  = acos(-1.0);

int gcd(int a,int b){return b?gcd(b,a%b):a;}
int dx[4]={1,0,-1,0};
int dy[4]={0,1,0,-1};

static const int N = 100;



int main(int argc, char const *argv[]) {
  cin.tie(0); ios::sync_with_stdio(false);
  int n;
  int p[N+1]; //M_i が p[i-1]行 p[i]列 となる
  int m[N+1][N+1]; //M_i ~ M_jまでをかけあわせたときの最小の掛け算の数
  std::cin >> n;
  REP1(i,n) std::cin >> p[i-1] >> p[i];
  REP1(i,n) m[i][i]=0;

  FOR(l, 2, n){
    REP1(i, n-l+1){
      int j = i+l-1;
      m[i][j] = INTINF;
      FOR(k, i, j-1){
        m[i][j] = min(m[i][j], m[i][k] + m[k+1][j] + p[i-1]*p[k]*p[j]);
      }
    }
  }

  std::cout << m[1][n] << '\n';

  return 0;
}

C++: #include <iostream>
#include <limits>

constexpr int MAXN = 100;
int C[MAXN + 1][MAXN + 1];
int M[MAXN][2];

int main() {
    int n;
    std::cin >> n;
    for (int i = 0; i < n; i++) {
        std::cin >> M[i][0] >> M[i][1];
    }

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

    for (int j = 1; j < n; j++) {
        for (int i = j - 1; i >= 0; i--) {
            C[i][j] = std::numeric_limits<int>::max();
            for (int k = i; k < j; k++) {
                C[i][j] = std::min(C[i][j], C[i][k] + C[k+1][j] + M[i][0] * M[j][1] * M[k][1]);
            }
        }
    }
    std::cout << C[0][n-1] << std::endl;
}

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

typedef vector<int> VI;
typedef vector<VI> VVI;
typedef vector<string> VS;
typedef pair<int,int> PII;
typedef long long LL;

#define d(x)  cout<<#x<<" = "<<(x)<<endl;
#define ALL(a)  (a).begin(),(a).end()
#define RALL(a) (a).rbegin(), (a).rend()
#define PB push_back
#define MP make_pair
#define SZ(a) int((a).size())
#define EACH(i,c) for(typeof((c).begin()) i=(c).begin(); i!=(c).end(); ++i)
#define REACH(i,c) for(typeof((c).rbegin()) i=(c).rbegin(); i!=(c).rend(); ++i)
#define EXIST(s,e) ((s).find(e)!=(s).end())
#define SORT(c,n) sort(c,c+n)
#define VSORT(c) sort((c).begin(),(c).end())
#define FOR(i,a,b) for(int i=(a);i<(b);++i)
#define REP(i,n)  FOR(i,0,n)
#define DFOR(i,b,a) for(int i=(b)-1;i>=(a);--i)
#define DREP(i,n) DFOR(i,n,0)
#define INF 2000000000

const double EPS = 1e-10;
const double PI  = acos(-1.0);
////////////////////////////////////////////////
int n,dp[110][110],p[110];


int main()
{
	cin>>n;
	FOR(i,1,n+1)
	{
		cin>>p[i-1]>>p[i];
	}
	FOR(i,1,n+1)
	{
		dp[i][i]=0;
	}
	FOR(l,2,n+1)
	{
		FOR(i,1,n-l+2)
		{
			int j=i+l-1;
			dp[i][j]=INF;
			FOR(k,i,j)
			{
				dp[i][j]=min(dp[i][j],dp[i][k]+dp[k+1][j]+p[i-1]*p[k]*p[j]);
			}
		}
	}
	cout<<dp[1][n]<<endl;
	return 0;
}

C++: #include<iostream>
#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
#define rep(i,n) for(int i=0;i<n;i++)

/* 大文字を小文字に変換 */
char tolower(char c) {return (c + 0x20);}
/* 小文字を大文字に変換 */
char toupr(char c) {return (c - 0x20);}

// if('A'<=s[i] && s[i]<='Z') s[i] += 'a'-'A';

/*
string s = "abcdefg"
s.substr(4) "efg"
s.substr(0,3) "abc"
s.substr(2,4) "cdef"
*/

const int INFTY = pow(10, 8);

int main()
{
    int n; cin >> n;
    int p[n+1];
    int m[n+1][n+1];
    rep(i,n){
        m[i][i] = 0;
        int p1, p2; cin >> p1 >> p2;
        p[i] = p1;
        if(i == n-1){
            m[i+1][i+1] = 0;
            p[i+1] = p2;
        }
    }

    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; 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;
}

C++: #include <stdio.h>
#include <iostream>
#define INFTY 200000000
using namespace std;

int main(void){
    int n;
    int m[100][100];
    int p[101];

    scanf("%d", &n);
    for(int i = 0; i < n; i++){
        scanf("%d", &p[i]);
        scanf("%d", &p[i + 1]);
    }

    for(int i = 0; i < n; i++){
        for(int j = 0; j < n; j++){
            if(i > j)
                m[i][j] = INFTY;
            if(i == j) 
                m[i][j] = 0;
        }
    }
    
    for(int i = 0; i <= n - 2; i++){
        m[i][i + 1] = p[i] * p[i + 1] * p[i + 2];
    }

    for(int k = 2; k <= n - 1; k++){
        for(int i = 0; i + k <= n - 1; i++){
            m[i][i + k] = INFTY;
            for(int t = 0; t + 1 <= k; t++){
                m[i][i + k] = min(m[i][i + t] + m[i + t + 1][i + k] + p[i] * p[i + t + 1] * p[i + k + 1], m[i][i + k]);
            }
        }
    }

    printf("%d\n", m[0][n - 1]);

}

C++: #include <iostream>
#include <string>
#include <algorithm>
#include <vector>

using namespace std;
static const int N = 100;


void solve(vector<int> &data)
{
	vector<vector<int>> dp(N + 1, vector<int>(N + 1, 0));

	int nums = data.size() - 1;
	for (int len = 2; len <= nums; ++len)
	{
		for (int l = 1; l <= nums - len + 1; ++l)
		{
			int r = l + len - 1;
			dp[l][r] = INT_MAX;
			for (int m = l; m <= r - 1; ++m)
			{
				cout << len << " " << l << " " << r << endl;
				dp[l][r] = min(dp[l][r], dp[l][m] + dp[m+1][r] + data[l - 1] * data[m] * data[r]);
			}
		}
	}

	cout << dp[1][nums] << endl;
}

int main()
{
	int num; cin >> num;
	vector<int> data(num + 1);
	for (int i = 1; i <= num; ++i)
		cin >> data[i-1] >> data[i];

	solve(data);
}