Codeforces Round #829 (Div. 2) D Factorial Divisibility

Factorial Divisibility

模拟

合....合成大西瓜？

枚举每个阶乘因子，提取公因式之后有很多散着的 \(1\)，然后判断能不能合成当前倍数

#include <iostream>
#include <cstdio>
#include <algorithm>
#include <vector>
using namespace std;
typedef long long ll;
#define pii pair<int, int>
const ll maxn = 2e5 + 10;
const ll inf = 1e17 + 10;

int main()
{
    ios::sync_with_stdio(false);
    cin.tie(0);
    cout.tie(0);
    vector<int>vis(500001, 0);
    int n, m;
    cin >> n >> m;
    int minn = 1e9;
    for(int i=0; i<n; i++)
    {
        int x;
        cin >> x;
        minn = min(minn, x);
        vis[x]++;
    }
    int f = 1, now = 0;
    for(int i=1; i<=m; i++)
    {
        if(now % i) f = 0;
        now /= i;
        now += vis[i];
    }
    if(f) cout << "Yes\n";
    else cout << "No\n";
    cout << endl;
    return 0;
}