# PAT 解题报告 1037. Magic Coupon (25)

### 1037. Magic Coupon 题目描述：

The magic shop in Mars is offering some magic coupons. Each coupon has an integer N printed on it, meaning that when you use this coupon with a product, you may get N times the value of that product back! What is more, the shop also offers some bonus product for free. However, if you apply a coupon with a positive N to this bonus product, you will have to pay the shop N times the value of the bonus product… but hey, magically, they have some coupons with negative N’s!

For example, given a set of coupons {1 2 4 -1}, and a set of product values {7 6 -2 -3} (in Mars dollars M$) where a negative value corresponds to a bonus product. You can apply coupon 3 (with N being 4) to product 1 (with value M$7) to get M$28 back; coupon 2 to product 2 to get M$12 back; and coupon 4 to product 4 to get M$3 back. On the other hand, if you apply coupon 3 to product 4, you will have to pay M$12 to the shop.

Each coupon and each product may be selected at most once. Your task is to get as much money back as possible.

### 1037. Magic Coupon 算法分析：

#include <iostream>
#include <cstring>
#include <cstdio>
#include <cmath>
#include <algorithm>
#include <string>
#include <vector>
#include <map>
#include <iomanip>

#define nmax 100005
using namespace std;

int NC;
int NP;
int minimum;
long long money;

int coupons[nmax];
int products[nmax];

int compare(const void * a, const void * b) { return -( *(int*)a - *(int*)b ); }

void gao(void) {
qsort(coupons,NC,sizeof(int),compare);
qsort(products,NP,sizeof(int),compare);
int count = 0;
int c = 0;
long long prod = coupons1*products1;
while(prod > 0 && count<minimum) {
count++;
money += prod;
c++;
prod = coupons1*products1;
}
c=1;
prod = coupons[NC-c]*products[NP-c];
while(prod>0 && count<minimum) {
count++;
money += prod;
c++;
prod = coupons[NC-c]*products[NP-c];
}
return ;
}

int main(void) {
cin>>NC;
for(int i=0; i<NC; i++) cin>>coupons[i];
cin>>NP;
for(int i=0; i<NP; i++) cin>>products[i];
money = 0;
minimum = min(NC,NP);
gao();
cout<<money<<endl;
return 0;
}


### 1037. Magic Coupon 注意点：

Written on December 29, 2013