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1854. Maximum Population Year

Difficulty Topics

Description

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

maximum-population-year.py
class Solution:
    def maximumPopulation(self, logs: List[List[int]]) -> int:
        people = [0] * 2051

        for b,d in logs:
            people[b] += 1
            people[d] -= 1

        for i in range(1, 2051):
            people[i] += people[i - 1]

        res = 0
        mmax = float('-inf')
        for i,x in enumerate(people):
            if x > mmax:
                res = i
                mmax = x

        return res