AtCoder Beginner Contest 144 [ D - Water Bottle ] https://atcoder.jp/contests/abc144/tasks/abc144_d

abc144_d.py

'''
[問題]
https://atcoder.jp/contests/abc144/tasks/abc144_d
 数学問題

[解説]
https://blog.hamayanhamayan.com/entry/2019/10/27/233430

https://img.atcoder.jp/abc144/editorial.pdf
'''

import sys
import math

sys.setrecursionlimit(10 ** 6)  # 再帰上限の引き上げ
input = sys.stdin.readline

INF = 2 ** 63 - 1

a, b, x = map(int, input().split())

# 水筒の体積の半分を計算
half = a * a * b / 2.0

if x < half:
    # 水の体積が水筒の半分以下
    y = 2 * x / ( a * b)
    ans = math.atan(b / y)
else:
    # 水の体積が水筒の半分以上
    y = 2 * b - 2 * x / (a * a)
    ans = math.atan(y / a)

ans = math.degrees(ans)
print(ans)