Go: package main

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

func nextInt(sc *bufio.Scanner) int {
	sc.Scan()
	v, _ := strconv.Atoi(sc.Text())
	return v
}

func min(x, y int) int {
	if x > y {
		return y
	}
	return x
}

func main() {
	sc := bufio.NewScanner(os.Stdin)
	sc.Split(bufio.ScanWords)

	n := nextInt(sc)

	P := make([]int, n+1)
	for i := 1; i <= n; i++ {
		l := nextInt(sc)
		P[i-1] = l
		m := nextInt(sc)
		P[i] = m
	}

	matrix := make([][]int, n+1)
	for i := 0; i < n+1; i++ {
		matrix[i] = make([]int, n+1)
	}

	for l := 2; l <= n; l++ {
		for i := 1; i <= n - l + 1; i++ {
			j := i + l - 1
			matrix[i][j] = (1 << 21)
			for k := i; k <= j-1; k++ {
				matrix[i][j] = min(matrix[i][j], matrix[i][k] + matrix[k+1][j] + P[i-1] * P[k] * P[j])
			}
		}
	}
	fmt.Println(matrix[1][n])
}

C++: #include <iostream>
#include <algorithm> // next_permutation
#include <iomanip>
#include <cmath>
#include <vector>
#include <sstream>
#include <string>
#include <cstdio>
#include <stack>
#include <queue>
#include <list>
#include <numeric> //accumulate
//#include <unordered_map> //???????????\??¢??°
#include <fstream> //ifstream, ofstream

//#define NDEBUG //NDEBUG???#include <cassert>???????????????????????????????????´???assert?????????????????????????????????NDEBUG?????????????????????????????????????????????
#include <cassert> //assert


using namespace std;

//???????????°??????TEST????????????????????¬???????????????????????????????????¢????????????
#define TEST //*******************************************************************************************************************************************
//?????????????????¨??§?????\????????????????????????????????°?????????????¨???????????????????dout???????????????????????§???????????¬??????????????????????????????????????????
//??????????????????????????????????????????????????????????§?CPU???????£??????????????????§???TLE?????????????????????????????????????????§????????¨???                           ????????????????????????cerr????????£????????????????????????????????????
#ifdef TEST
#define dout cout
#define din cin
#else
stringstream dummy; //???????????°??????dout?????????????????????????????????
#define dout dummy.str(""); dummy.clear(stringstream::goodbit); dummy //dummy?????????????????????????????????????????¨?????¢?????¢???????????????
//???????????¨??????????????????goodbit?????????????????????????????¨???????????´????????????????????????????????¨?????°?????????????????§???????????????????????????????????? http://d.hatena.ne.jp/linden/20060427/p1
#endif

//?¨??????????????????????????????????????????????????????´??????OUTPUTFILE????????????????????¬???????????????????????????????????¢????????????
//#define OUTPUTFILE "output.txt" //*******************************************************************************************************************************************
#ifdef OUTPUTFILE
#define dout outputfile //??¨????????????TLE????????§?????????dout?????¨??¨??????????????¢????????????????????????????????????????????§????¨????????????´??????????????£??????????????????????¨?????????????????????????????????????????????§?????????????????????
ofstream outputfile(OUTPUTFILE);
#define OutputFilePath "/Users/Nag/Documents/Prgm/Test/DerivedData/Test/Build/Products/Debug/output.txt"
#endif

//?¨??????\???????????????????????????????????????????????´??????INPUTFROMTEXTFILE????????????????????¬???????????????????????????????????¢????????????
//#define INPUTFILE "input.txt" //*******************************************************************************************************************************************
#ifdef INPUTFILE
#define din inputfile
ifstream inputfile(INPUTFILE);
#endif


#define disp(A) dout << #A << " = " << (A) << endl
#define disP(A) dout << setw(3) << (A) << " " // << setw(3) ??????????????\????????????
#define rep(i,a,n) for(int (i)=(a); (i)<(n); (i)++)

#define dispAll(A,n) dout << #A << " = "; rep(j, 0, (n)) {disP(A[j]);} dout << endl

typedef pair<int,int> pii;
typedef vector<int> vi;
typedef unsigned long long ll;

const int INF = 1e9-1;

int N;
int R[101];
int C[101];

int solve(int n, int r[], int c[]) {
    if(n==2) {
        assert(c[0]==r[1]);
        return r[0]*c[0]*c[1];
    }
    
    int min = INF;
    int tmp;
    rep(i,0,n-1) {
        
        //M[i]*M[i+1]?????????????????¨??????r[],c[]?????????
        int rr[n-1], cc[n-1];
        rep(j,0,n-1) {
            if(j<i) {
                rr[j] = r[j];
                cc[j] = c[j];
            }
            else if(j==i) {
                rr[j] = r[i];
                cc[j] = c[i+1];
            }
            else {
                rr[j] = r[j+1];
                cc[j] = c[j+1];
            }
        }
        
        //M[i]*M[i+1]?????????????´???°???1????????£???n-1??¨?????£?????????????????°???????§£???
        //????????????ans???M[i]*M[i+1]????¨?????????°??????????????????
        assert(c[i]==r[i+1]);
        tmp = solve(n-1, rr, cc) + r[i]*c[i]*c[i+1];
        
        if(tmp<min) min = tmp;
    }
    
    assert(min!=INF);
    return min;
}


int main() {
    din >> N;
    rep(i,0,N) {
        din >> R[i] >> C[i];
    }
    
    dout << solve(N, R, C) << endl;
    
    
#ifdef INPUTFILE
    inputfile.close();
#endif
    
#ifdef OUTPUTFILE
    outputfile.close();
    cout << "\"" << OutputFilePath << "\"" << endl;
#endif
    
    return 0;
}

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

// 総数を1000000007で割った余り
const long long mod = 1e9 + 7;

using ll  = long long;
using pii = pair<int, int>;
using pll = pair<ll, ll>;
#define ull unsigned long long
#define ld long double
#define vi vector<int>
#define vll vector<ll>
#define vc vector<char>
#define vs vector<string>
#define vpii vector<pii>
#define vpll vector<pll>

#define rep(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 repr(i, n) for (int i = ((int)(n)-1); i >= 0; i--)
#define rep1r(i, n) for (int i = ((int)(n)); i >= 1; i--)

#define sz(x) ((int)(x).size())
#define all(x) (x).begin(), (x).end()
#define rall(x) (x).rbegin(), (x).rend()

#define SORT(v, n) sort(v, v + n);
// #define SORT(v, n) stable_sort(v, v + n);
#define VSORT(v) sort(v.begin(), v.end());
#define RSORT(x) sort(rall(x));
#define pb push_back
#define mp make_pair

#define INF (1e9)
#define PI (acos(-1))
#define EPS (1e-7)

ull gcd(ull a, ull b) { return b ? gcd(b, a % b) : a; }
ull lcm(ull a, ull b) { return a / gcd(a, b) * b; }

static const int N = 100;

int main() {
    ios::sync_with_stdio(false);
    cin.tie(0);
    // cout << fixed << setprecision(5);

    int n;
    cin >> n;
    int p[N + 1], m[N + 1][N + 1];
    rep1(i, n) { cin >> p[i - 1] >> p[i]; }
    rep1(i, n) 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;

const int INF = 1 << 30;
int n;
vector<int> r, c;
vector<vector<int>> dp;

int dfs(int a, int b) {
    if (dp[a][b] != INF) return dp[a][b];
    if (a + 1 == b) return dp[a][b] = 0;
    int res = INF;
    for (int k = a + 1; k < b; ++k) {
        res = min(res, dfs(a, k) + dfs(k, b) + r[a] * r[k] * c[b - 1]);
    }
    return dp[a][b] = res;
}

int main() {
    cin >> n;
    r.resize(n);
    c.resize(n);
    for (int i = 0; i < n; ++i) {
        cin >> r[i] >> c[i];
    }
    dp.resize(n + 1, vector<int>(n + 1, INF));
    cout << dfs(0, n) << endl;
}