Find the year with the most number of people alive in Python

Question

Given a list of people with their birth and end years (all between 1900 and 2000), find the year with the most number of people alive.

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Answer 1

1. Just put the birth and death years into a dict. If it is birth, increase the value by 1. or vice versa.
2. Sort the dict by keys and iterate by reading the current number of the alive people.

3. Follow the 'maxAlive' an 'theYear' to get the first year with the highest number

   years = {} 
   
   for p in people:
       if p.birth in years:
           years[p.birth] += 1
       else:
           years[p.birth] = 1
   
       if p.death in years:
           years[p.death] -= 1
       else:
           years[p.death] = -1
   
   alive = 0
   maxAlive = 0
   theYear = people[0].birth
   for year in sorted(years):
       alive += years[year]
       if alive > maxAlive:
           maxAlive = alive
           theYear = year