1037. Magic Coupon (25), 1037 coupon

1037. Magic Coupon (25), 1037 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

#include <iostream>#include <algorithm>#include <vector>using namespace std;vector<int> nc_p;vector<int> nc_n;vector<int> np_p;vector<int> np_n;bool cmp1(int a, int b) {    return a > b;}bool cmp2(int a, int b) {    return a < b;}int main() {    int nc, np, i, tmp;    while(cin>>nc) {        for(i=0; i<nc; i++) {            cin>>tmp;            if(tmp >= 0) {                nc_p.push_back(tmp);            } else {                nc_n.push_back(tmp);            }        }        cin>>np;        for(i=0; i<np; i++) {            cin>>tmp;            if(tmp >= 0) {                np_p.push_back(tmp);            } else {                np_n.push_back(tmp);            }        }        sort(nc_p.begin(), nc_p.end(), cmp1);        sort(nc_n.begin(), nc_n.end(), cmp2);        sort(np_p.begin(), np_p.end(), cmp1);        sort(np_n.begin(), np_n.end(), cmp2);                int sum = 0;                for(i=0; i<nc_p.size() && i<np_p.size(); i++) {            sum += nc_p[i] * np_p[i];        }        for(i=0; i<nc_n.size() && i<np_n.size(); i++) {            sum += nc_n[i] * np_n[i];        }        cout<<sum<<endl;        nc_p.clear();        nc_n.clear();        np_p.clear();        np_n.clear();    }    return 0;}