Sicily-1438

一．      题意

买二送一。排序之后隔三求和，求折扣的最大值。

二．      代码

 1 //

 2 //  main.cpp

 3 //  sicily-1438

 4 //

 5 //  Created by ashley on 14-11-7.

 6 //  Copyright (c) 2014年 ashley. All rights reserved.

 7 //

 8 

 9 #include <iostream>

10 #include <algorithm>

11 using namespace std;

12 

13 int prices[20000];

14 

15 int main(int argc, const char * argv[])

16 {

17     int cases , items;

18     cin >> cases;

19     while (cases--) {

20         cin >> items;

21         for (int i = 0; i < items; i++) {

22             cin >> prices[i];

23         }

24         sort(prices, prices + items);

25         int sum = 0;

26         for (int i = items - 3; i >= 0; i = i - 3) {

27             sum = sum + prices[i];

28         }

29         cout << sum << endl;

30     }

31     

32     return 0;

33 }