1070. Mooncake (25)

struct mooncakeNode{
double amount;//需要使用double，才能通过测试点2
double price;
double unitPrice;
mooncakeNode() :amount(0), price(0), unitPrice(0){};
};

//#include<string>
//#include<stack>
//#include<unordered_set>
//#include <sstream>
//#include "func.h"
//#include <list>
#include <iomanip>
#include<unordered_map>
#include<set>
#include<queue>
#include<map>
#include<vector>
#include <algorithm>
#include<stdio.h>
#include<iostream>
#include<string>
#include<memory.h>
#include<limits.h>
#include<stack>
using namespace std;
/*
3 2000
180 150 100
7.5 7.2 4.5
3 20
180 150 100
7.5 7.2 4.5

0 20

3 0
180 150 100
7.5 7.2 4.5

3 1
180 150 100
7.5 7.2 4.5
*/
struct mooncakeNode{
double amount;//需要使用double，才能通过测试点2
double price;
double unitPrice;
mooncakeNode() :amount(0), price(0), unitPrice(0){};
};
bool cmp(const mooncakeNode&a, const mooncakeNode&b)
{
if (a.amount == b.amount && a.price >= b.price) return true;
else
return (double)a.price*b.amount > (double)b.price*a.amount;
}
int main(void)
{

int n, marketNeed;
cin >> n >> marketNeed;
vector<mooncakeNode> mooncake(n);
for (int i = 0; i < n; i++)
{
cin >> mooncake[i].amount;
}
for (int i = 0; i < n; i++)
{//输入总价格和求出单位价格
cin >> mooncake[i].price;
if (mooncake[i].amount == 0)
{
mooncake[i].price = 0;
mooncake[i].unitPrice = 0;
}
else
mooncake[i].unitPrice = mooncake[i].price / mooncake[i].amount;
}
sort(mooncake.begin(), mooncake.end(), cmp);

double profit=0;
for (int i = 0; i < n && marketNeed!=0; i++)
{
if (mooncake[i].amount == marketNeed)
{//如果刚好相等，则全部要了
profit += mooncake[i].price;
marketNeed -= mooncake[i].amount;
}
else if (mooncake[i].amount < marketNeed)
{//如果数量小于市场需要，则全部要了
profit += mooncake[i].price;
marketNeed -= mooncake[i].amount;
}
else
{//如果数量大于市场需要，则取市场需要部分即可
profit += mooncake[i].price*marketNeed/mooncake[i].amount;
marketNeed = 0;
}
}
printf("%.2lf", profit);
//cout << setprecision(2) << profit << endl;

return 0;
}