题库练习 Distance
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A14715 | Distance

时间限制1s
内存限制256MB
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题目描述

Let's denote the Manhattan distance between two points $p_1$ (with coordinates $(x_1, y_1)$ ) and $p_2$ (with coordinates $(x_2, y_2)$ ) as $d(p_1, p_2) = |x_1 - x_2| + |y_1 - y_2|$ . For example, the distance between two points with coordinates $(1, 3)$ and $(4, 2)$ is $|1 - 4| + |3 - 2| = 4$ .

You are given two points, $A$ and $B$ . The point $A$ has coordinates $(0, 0)$ , the point $B$ has coordinates $(x, y)$ .

Your goal is to find a point $C$ such that:

- both coordinates of $C$ are non-negative integers;
- $d(A, C) = \dfrac{d(A, B)}{2}$ (without any rounding);
- $d(B, C) = \dfrac{d(A, B)}{2}$ (without any rounding).

Find any point $C$ that meets these constraints, or report that no such point exists.

输入格式

The first line contains one integer $t$ ( $1 \le t \le 3000$ ) — the number of test cases.

Each test case consists of one line containing two integers $x$ and $y$ ( $0 \le x, y \le 50$ ) — the coordinates of the point $B$ .

输出格式

For each test case, print the answer on a separate line as follows:

- if it is impossible to find a point $C$ meeting the constraints, print "-1 -1" (without quotes);
- otherwise, print two non-negative integers not exceeding $10^6$ — the coordinates of point $C$ meeting the constraints. If there are multiple answers, print any of them. It can be shown that if any such point exists, it's possible to find a point with coordinates not exceeding $10^6$ that meets the constraints.

输入输出样例

输入 #1
10
49 3
2 50
13 0
0 41
42 0
0 36
13 37
42 16
42 13
0 0
输出 #1
23 3
1 25
-1 -1
-1 -1
21 0
0 18
13 12
25 4
-1 -1
0 0
C++ 编辑器
输入
输出