Submission #2694717

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Source Code Expand

from itertools import accumulate, chain
 
n, c = map(int, input().split())
xs, vs = zip(*(map(int, input().split()) for _ in range(n)))
 
ds = [j - i for i, j in zip(chain([0], xs), chain(xs, [c]))]
 
clockwise1      = chain([0], (v - d*2 for v, d in zip(accumulate(vs), accumulate(ds))))
anticlockwise1  = chain([0], (v - d for v, d in zip(accumulate(vs[::-1]), accumulate(ds[::-1]))))
clock_anticlock = (x + y for x, y in zip(clockwise1, reversed(list(accumulate(anticlockwise1, func=max)))))
 
anticlockwise2  = chain([0], (v - d*2 for v, d in zip(accumulate(vs[::-1]), accumulate(ds[::-1]))))
clockwise2      = chain([0], (v - d for v, d in zip(accumulate(vs), accumulate(ds))))
anticlock_clock = (x + y for x, y in zip(anticlockwise2, reversed(list(accumulate(clockwise2, func=max)))))
 
print(max(chain(clock_anticlock, anticlock_clock)))

Submission Info

Judge Result