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- #!/usr/bin/env python3
- import sys
- import re
- from functools import reduce
- from math import ceil, sqrt
- from operator import mul
- def wins(time, distance):
- # invariant: hold * (time - hold) > distance
- # solve: -hold^2 + time*hold - distance = 0
- # hold = (time +- sqrt(time^2 - 4 * distance)) / 2
- # = (time +- d) / 2
- # solution: (time - d) / 2 < hold < (time + d) / 2
- d = sqrt(time ** 2 - 4 * distance)
- return int((time + d) / 2) - ceil((time - d) / 2) + 1 - 2 * (d % 1 == 0)
- times, distances = (re.findall(r'\d+', line) for line in sys.stdin)
- print(reduce(mul, (wins(int(t), int(d)) for t, d in zip(times, distances))))
- print(wins(int(''.join(times)), int(''.join(distances))))
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