Submission #1100562

#	Time	Username	Problem	Language	Result	Execution time	Memory
1100562		vjudge1	Star triangles (IZhO11_triangle)	Pypy 2	0 / 100	26 ms	19760 KiB

triangle

from collections import defaultdict
n = int(input())
stars = []
for _ in range(n):
    x, y = map(int, input().split())
    stars.append((x, y))
xc = defaultdict(int)
yc = defaultdict(int)
for x, y in stars:
    xc[x] += 1
    yc[y] += 1
total_triangles = 0
mp = defaultdict(int)
for x, y in stars:
    mp[(x, y)] += 1
for x, y in stars:
    x_leg = xc[x] - mp[(x, y)]
    y_leg = yc[y] - mp[(x, y)]
    total_triangles += x_leg * y_leg
print(total_triangles)

• Subtask 1: 0 / 100