Codeforces 27E. Number With The Given Amount Of Divisors (暴力)

题目链接：http://codeforces.com/problemset/problem/27/E

暴力

//#pragma comment(linker, "/STACK:102400000, 102400000")
#include <algorithm>
#include <iostream>
#include <cstdlib>
#include <cstring>
#include <cstdio>
#include <vector>
#include <cmath>
#include <ctime>
#include <list>
#include <set>
#include <map>
using namespace std;
typedef long long LL;
typedef pair <int, int> P;
const int N = 1e5 + 5;
int a[20];
LL ans, p[] = {1, 2, 3, 5, 7, 11, 13, 17, 19, 23, 29}, limit = 1e18;

void dfs(int num, int len) {
    if(num == 1) {
        LL res = 1;
        for(int i = 1; i <= len; ++i) {
            for(int j = 1; j < a[i]; ++j) {
                if(limit / p[i] <= res) {
                    return ;
                }
                res *= p[i];
            }
        }
        ans = min(ans, res);
        return ;
    }
    for(int i = 2; i <= num; ++i) {
        if(num % i == 0) {
            a[len + 1] = i;
            dfs(num / i, len + 1);
        }
    }
}

int main()
{
    int n;
    cin >> n;
    if(n == 1) {
        cout << 1 << endl;
        return 0;
    } else if(n == 2) {
        cout << 2 << endl;
        return 0;
    }
    ans = limit;
    for(int i = 1; i <= n; ++i) {
        if(n % i == 0) {
            a[1] = i;
            dfs(n/i, 1);
        }
    }
    cout << ans << endl;
    return 0;
}