301590: CF301A. Yaroslav and Sequence
Memory Limit:256 MB
Time Limit:2 S
Judge Style:Text Compare
Creator:
Submit:0
Solved:0
Description
Yaroslav and Sequence
题意翻译
### 题目描述 现有 $2n-1$ 个整数,每次操作可以使其中的 $n$ 个数 $\times (-1)$。 现在请问进行任意次操作后,这些整数的最大和是多少? --- ### 输入格式 输入共两行。第一行包含一个整数 $n$。 第二行包含 $2n-1$ 个数,表示所给的整数。 --- ### 输出格式 输出一个整数,表示最大和。 --- ### 数据范围 对于 $100\%$ 的数据,$1\le n\le100,1\le|x|\le1000$题目描述
Yaroslav has an array, consisting of $ (2·n-1) $ integers. In a single operation Yaroslav can change the sign of exactly $ n $ elements in the array. In other words, in one operation Yaroslav can select exactly $ n $ array elements, and multiply each of them by -1. Yaroslav is now wondering: what maximum sum of array elements can be obtained if it is allowed to perform any number of described operations? Help Yaroslav.输入输出格式
输入格式
The first line contains an integer $ n $ $ (2<=n<=100) $ . The second line contains $ (2·n-1) $ integers — the array elements. The array elements do not exceed $ 1000 $ in their absolute value.
输出格式
In a single line print the answer to the problem — the maximum sum that Yaroslav can get.
输入输出样例
输入样例 #1
2
50 50 50
输出样例 #1
150
输入样例 #2
2
-1 -100 -1
输出样例 #2
100