[BOJ/백준] 13334 철로

import heapq
def check(D):
    global result
    possible_set = []
 
    while rail_list:
        END,START = heapq.heappop(rail_list)
        if END-D <=START:
            heapq.heappush(possible_set,START)
        while possible_set and possible_set[0] < END-D:
            heapq.heappop(possible_set)
        
        result = max(result,len(possible_set))
 
 
 
 
N = int(input())
rail_list = []
for idx in range(N):
    A,B = map(int,input().split())
    if A > B:
        A,B = B,A
    heapq.heappush(rail_list,(B,A))
 
d = int(input())
result = 0
check(d)
print(result)

 

 

import heapq
 
N = int(input())
rail_list = []
for idx in range(N):
    A,B = map(int,input().split())
    if A > B:
        A,B = B,A
    rail_list.append((A,B))
rail_list.sort(key=lambda x : x[1])
 
in_rail = []
d = int(input())
result = 0
for start,end in rail_list:
    if end-d <= start:
        heapq.heappush(in_rail,start)
    while in_rail and end-d > in_rail[0]:
        heapq.heappop(in_rail)
    result = max(result,len(in_rail))
print(result)