P9022 - a-b Problem

内存限制：256 MB 时间限制：3 S

题面：传统评测方式：文本比较上传者：

提交：9 通过：6

Alice and Bob are playing a little game. There are

n

stones. Alice and Bob take turns picking stones, with Alice going first. Each person can only pick one stone at a time until all the stones are gone. Each stone has two attributes,

A_{i}

and

B_{i}

. When Alice picks a stone, she earns

A_{i}

points, and when Bob picks a stone, he earns

B_{i}

points. The total score for each person is the sum of the points they earn when picking a stone. Both players want to maximize the difference between their scores, aiming to have their own score minus the opponent's score as large as possible. The question is, what is the final result of Alice's score minus Bob's score?

The first line contains a positive integer, $T$ , representing the number of test cases, where $1 \leq T \leq 20$ .

Next, for each test case, the following format is repeated:

The first line contains a positive integer, $n$ , where $1 \leq n \leq 1 0^5$ . The next $n$ lines contain two integers, $A_{i}$ and $B_{i}$ , representing the two attributes of the ith stone. The values of $A_{i}$ and $B_{i}$ satisfy $0 \leq A_{i}, B_{i} \leq 1 0^9$ .

For each test case, output one line containing an integer representing the answer.

1
-1

9022: a-b Problem

题目描述

输入格式

输出格式

输入样例复制

输出样例复制