1037 Magic Coupon
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.
Input Specification:
Each input file contains one test case. For each case, the first line contains the number of coupons NC, followed by a line with NC coupon integers. Then the next line contains the number of products NP, followed by a line with NP product values. Here 1≤NC,NP≤105, and it is guaranteed that all the numbers will not exceed 230.
Output Specification:
For each test case, simply print in a line the maximum amount of money you can get back.
Sample Input:
4
1 2 4 -1
4
7 6 -2 -3
Sample Output:
43
running code:
#include<cstdio>
#include<algorithm>
using namespace std;
const int maxn=100010;
int coupon[maxn],product[maxn];
int main()
{
int m,n;
scanf("%d",&n);
for(int i=0;i<n;i++)
{
scanf("%d",&coupon[i]);
}
scanf("%d",&m);
for(int i=0;i<m;i++)
{
scanf("%d",&product[i]);
}
sort(coupon,coupon+n);//从小到大排序
sort(product,product+m);//从小到大排序
int i=0,j,ans=0;
while(i<n&&i<m&&coupon[i]<0&&product[i]<0)//负数集合相乘累加
{
ans+=coupon[i]*product[i];
i++;
}
i=n-1;
j=m-1;
while(i>=0&&j>=0&&coupon[i]>0&&product[j]>0)//正数集合相乘累加
{
ans+=coupon[i]*product[j];
i--;
j--;
}
printf("%d\n",ans);
return 0;
}