Maximum Population Year

#leetcode #dsa #theabbie

You are given a 2D integer array logs where each logs[i] = [birthi, deathi] indicates the birth and death years of the ith person.

The population of some year x is the number of people alive during that year. The ith person is counted in year x's population if x is in the inclusive range [birthi, deathi - 1]. Note that the person is not counted in the year that they die.

Return the earliest year with the maximum population.

Example 1:

Input: logs = [[1993,1999],[2000,2010]]
Output: 1993
Explanation: The maximum population is 1, and 1993 is the earliest year with this population.

Example 2:

Input: logs = [[1950,1961],[1960,1971],[1970,1981]]
Output: 1960
Explanation:
The maximum population is 2, and it had happened in years 1960 and 1970.
The earlier year between them is 1960.

Constraints:

1 <= logs.length <= 100
1950 <= birthi < deathi <= 2050

SOLUTION:

import bisect

class Solution:
    def maximumPopulation(self, logs: List[List[int]]) -> int:
        pops = []
        for b, d in logs:
            bisect.insort(pops, (b, 1))
            bisect.insort(pops, (d, -1))
        mpop = 0
        mpopyear = None
        curr = 0
        for year, p in pops:
            curr += p
            if curr > mpop:
                mpop = curr
                mpopyear = year
        return mpopyear