题解 | #小欧的选数乘积#

暴力的添加最大的元素

#include <iostream>
#include <queue>
#include <map>
#include <set>
#include <cmath>
#include <cstring>
#include <algorithm>
#include <iomanip>
#include <stack>
#include <numeric>
#include <ctime>
#include <string>
#include <bitset>
#include <unordered_map>
#include <unordered_set>

using namespace std;
using ll = long long;

const ll N = 5e5 + 5, mod = 1e9 + 7, inf = 2e18;
const double esp = 1e-8;

ll x, y;
set<ll>st;
int n;

void solve() {
    cin >> x >> y >> n;

    for (int i = 1; i <= n; i++) {
        ll tem;
        cin >> tem;
        st.insert(tem);
    }

    if (x >= y) {
        cout << 0;
        return ;
    }
    int ans = 0;
    while (x < y && !st.empty()) {
        auto it = st.rbegin();
        x *= *it;
        ans++;
        st.erase(*it);
    }

    cout << (x >= y ? ans : -1);

}

int main() {
    ios::sync_with_stdio(0), cin.tie(0), cout.tie(0);

    int t = 1;
    //cin >> t;

    while (t--) {
        solve();
    }

    return 0;
}