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22031_Toxophily

2022-5-16 18:21| 发布者: Hocassian| 查看: 21| 评论: 0|原作者: 肇庆学院ACM合集

摘要:

C:\Users\Administrator\Downloads\2019-10-12-10-14-4-8950655596400-Problem List-采集的数据-后羿采集器.html

Pro.ID

22031

Title

Toxophily

Title链接

http://10.20.2.8/oj/exercise/problem?problem_id=22031

AC

Submit

Ratio

55.56%

时间&空间限制

Time Limit: 1000/500 MS (Java/Others) Memory Limit: 65536/32768 K (Java/Others)

描述

The recreation center of WHU ACM Team has indoor billiards, Ping Pang, chess and bridge, toxophily, deluxe ballrooms KTV rooms, fishing, climbing, and so on.

We all like toxophily.

Bob is hooked on toxophily recently. Assume that Bob is at point (0, 0) and he wants to shoot the fruits on a nearby tree. He can adjust the angle to fix the trajectory. Unfortunately, he always fails at that. Can you help him?

Now given the object's coordinates, please calculate the angle between the arrow and x-axis at Bob's point. Assume that g=9.8N/m.

输入

The input consists of several test cases. The first line of input consists of an integer T, indicating the number of test cases. Each test case is on a separated line, and it consists three floating point numbers: x, y, v.

x and y indicate the coordinate of the fruit.

v is the arrow's exit speed.

T ≤ 100

0 ≤ x, y, v ≤ 10000

输出

Description

The recreation center of WHU ACM Team has indoor billiards, Ping Pang, chess and bridge, toxophily, deluxe ballrooms KTV rooms, fishing, climbing, and so on.

We all like toxophily.

Now given the object's coordinates, please calculate the angle between the arrow and x-axis at Bob's point. Assume that g=9.8N/m.

Input

x and y indicate the coordinate of the fruit.

v is the arrow's exit speed.

T ≤ 100

0 ≤ x, y, v ≤ 10000

Output

For each test case, output the smallest answer rounded to six fractional digits on a separated line.

Output "-1", if there's no possible answer.

Please use radian as unit.

Sample Input