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 }