1037. Magic Coupon (25)PAT甲级

#include<stdio.h>
#include<algorithm>

#define MAX_N 100010
int coupon[MAX_N];
int product[MAX_N];

int main(){
int n,m;
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]);
}
std::sort(coupon,coupon+n);
std::sort(product,product+m);
int i=0,j,ans=0;
while(i<n&&i<m&&coupon[i]<0&&product[i]<0){
ans+=product[i]*coupon[i];
i++;
}
i=n-1;
j=m-1;
while(i>=0&&j>=0&&coupon[i]>0&&product[j]>0){
ans+=product[j]*coupon[i];
i--;j--;
}
printf("%d\n",ans);
return 0;
}