1020. 月饼.cpp

#include <bits/stdc++.h>
using namespace std;
using gg = long long;
int main() {
    ios::sync_with_stdio(false);
    cin.tie(0);
    gg ni, di;
    cin >> ni >> di;
    using ad2 = array<double, 2>;  //存储月饼的库存量和总售价
    vector<ad2> cakes(ni);
    for (gg i = 0; i < ni; ++i)
        cin >> cakes[i][0];
    for (gg i = 0; i < ni; ++i)
        cin >> cakes[i][1];
    //按单价从大到小排序
    sort(cakes.begin(), cakes.end(), [](const ad2& c1, const ad2& c2) {
        return c1[1] * 1.0 / c1[0] > c2[1] * 1.0 / c2[0];
    });
    double ans = 0.0;  //存储最终收益
    for (auto& c : cakes) {
        if (di >= c[0]) {
            ans += c[1];
            di -= c[0];
        } else {
            ans += c[1] * 1.0 / c[0] * di;
            di = 0;
        }
    }
    cout << fixed << setprecision(2) << ans;
    return 0;
}