boj 2841 [스택]

boj 2841

import sys

N, P = map(int,sys.stdin.readline().split())

# 빈 배열 6개 만들기!

st = [[] for _ in range(6)]
answer = 0
for _ in range(N):
	line, p = map(int,isys.stdin.readline().split())
	if st[line-1]:
		while st[line-1]:
			if p < st[line-1][-1]:
				st[line-1].pop()
				answer += 1
			elif p == st[line-1][-1]:
				break
			else:
				st[line-1].append(p)
				answer += 1
				break
		if not st[line-1]:
			st[line-1] = [p]
			answer += 1
	else:
		st[line-1] = [p]
		answer += 1
 
print(answer)