1037. Magic Coupon

Two arrays:NC[],NP[]

Supposed that two points (l1 and r1)start from the head and the tail of the array of NC seperately,in a similar way,exists two points(l2 and r2)points to the the head and end of the array of NP. 

l1 and l2 move to the right step by step guaranted that nc[l1]<0 and np[l2]<0,otherwise terminate.certainly we compute the product:NC[l1]*NC[l2] every step.

r1 and r2 move to the right step by step guaranted that nc[r1]>0 and np[r2]>0,otherwise terminate.certainly we compute the product:NC[r1]*NC[r2] every step.

// 1037. Magic Coupon.cpp: 主項目文件。

#include "stdafx.h"
#include <cstdio>
#include <algorithm>
using std::sort;

const int N=100003;
int nc[N],np[N];
int ncNum,npNum;

int maxProfit(){
	int l1=0,r1=ncNum-1,l2=0,r2=npNum-1;
	int profitSum=0;
	sort(nc,nc+ncNum);
	sort(np,np+npNum);
	while(l1<ncNum&&l2<npNum&&nc[l1]<0&&np[l2]<0)
		profitSum+=nc[l1]*np[l2],l1++,l2++;
	while(r1>=0&&r2>=0&&nc[r2]>0&&np[r2]>0)
		profitSum+=nc[r1]*np[r2],r1--,r2--;
	return profitSum;
}

int main()
{
	scanf("%d",&ncNum);
	for(int i=0;i<ncNum;i++)
		scanf("%d",nc+i);
	scanf("%d",&npNum);
	for(int i=0;i<npNum;i++)
		scanf("%d",np+i);
	int res=maxProfit();
	printf("%d\n",res);
    return 0;
}