PAT Basic Level 1020. 月饼（25）

【来源】

1020. 月饼（25）

【分析】

为了获取最大的利润，首先把月饼按照单价从高到低排序，然后依次购买，到满足需求为止。

【源码】

#include <iostream>#include <vector>#include <algorithm>#include <iomanip>using namespace std;struct mooncake{    double stock;    double money;};bool compare(mooncake lhs, mooncake rhs){    return lhs.money / lhs.stock < rhs.money / rhs.stock;}int main(){    int n, d;    cin >> n >> d;    vector<mooncake> cakes;    for (int i = 0; i < n; ++i){        mooncake mk;        cin >> mk.stock;        cakes.push_back(mk);    }    for (int i = 0; i < n; ++i){        cin >> cakes[i].money;    }    sort(cakes.rbegin(), cakes.rend(), compare);    double profit = 0;    for (int i = 0; i < n; ++i){        d -= cakes[i].stock;        if (d == 0){            profit += cakes[i].money;            break;        }        else if (d < 0){            d += cakes[i].stock;            profit += d * cakes[i].money/cakes[i].stock;            d = 0;            break;        }        else{            profit += cakes[i].money;        }    }    cout << setprecision(2) << fixed << profit << endl;    system("pause");    return 0;}

【点评】

此题用到了贪婪思想，为较简单的模拟题。