Submission #71692417

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Source Code Expand

import sys
input = sys.stdin.read
data = input().split()

index = 0
N = int(data[index])
index += 1
M = int(data[index])
index += 1

occupied = set()
count = 0

for _ in range(M):
    r = int(data[index])
    index += 1
    c = int(data[index])
    index += 1
    
    is_valid = True
    for dr in range(2):
        for dc in range(2):
            if (r + dr, c + dc) in occupied:
                is_valid = False
                break
        if not is_valid:
            break
    
    if is_valid:
        count += 1
        for dr in range(2):
            for dc in range(2):
                occupied.add((r + dr, c + dc))

print(count)

Submission Info

Judge Result