Submission #27207087

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Source Code Expand

from functools import cmp_to_key

area = lambda x, y: 3 if y < 0 else 2 if x < 0 else 1

def arg_cmp(p, q):
    ap = area(*p)
    aq = area(*q)
    if ap == aq:
        px, py = p
        qx, qy = q
        z = px * qy - py * qx
        return -1 if z > 0 else 1 if z < 0 else 0
    else:
        return -1 if ap < aq else 1

N = int(input())
points = [tuple(map(int, input().split())) for _ in range(N)]
points = [(x-1, y) for x, y in points]
points.sort(key=cmp_to_key(arg_cmp))
current = (1, 0)
ans = 0
for (x, y) in points:
    if arg_cmp((x+1, y-1), current) >= 0:
        ans += 1
        current = (x, y)
print(ans)

Submission Info

Judge Result