Restaurant Customers

Explanation

In this problem, n customers enter and leave a store at different times. We want to find the maximum number of customers in the store at any given time.

This can be done by storing the entering times as a tuple/pair of (enter_time, 1) and the leaving times as a tuple/pair of (leave_time, -1). Then, we sort the list of tuples/pairs by the first element of each tuple/pair. This way, we can iterate through the list of tuples/pairs and keep track of the number of customers in the store at any given time.

Code

import sys
input = sys.stdin.readline

customers = []
for _ in range(int(input())):
    enter, leave = map(int, input().split())
    customers.append((enter, 1))
    customers.append((leave, -1))
customers.sort()

count = 0
max_count = 0
for _, delta in customers:
    count += delta
    max_count = max(max_count, count)

print(max_count)