PAT (Advanced Level) 1070. Mooncake (25)

简单贪心。先买性价比高的。

#include<cstdio>
#include<cstring>
#include<cmath>
#include<vector>
#include<map>
#include<stack>
#include<queue>
#include<string>
#include<algorithm>
using namespace std;double eps=1e-7;
const int maxn=1000+10;
int n;
struct X
{double x;double y;
}s[maxn];
double money;bool cmp(const X&a,const X&b)
{return a.y/a.x>b.y/b.x;
}int main()
{scanf("%d",&n);scanf("%lf",&money);for(int i=1;i<=n;i++) scanf("%lf",&s[i].x);for(int i=1;i<=n;i++) scanf("%lf",&s[i].y);sort(s+1,s+1+n,cmp);double ans=0;for(int i=1;i<=n;i++){if(money>=s[i].x){ans=ans+s[i].y;money=money-s[i].x;}else{ans=ans+money*s[i].y/s[i].x;break;}}printf("%.2lf\n",ans);return 0;
}