h_index.py

"""
Task:
Given an array of integers citations where citations[i] is the number of
citations a researcher received for their ith paper, return compute the
researcher's h-index.

According to the definition of h-index on Wikipedia: A scientist has an
index h if h of their n papers have at least h citations each, and the other
n - h papers have no more than h citations each.

If there are several possible values for h, the maximum one is taken as the
h-index.

H-Index link: https://en.wikipedia.org/wiki/H-index

Implementation notes:
Use sorting of array

Leetcode link: https://leetcode.com/problems/h-index/description/

n = len(citations)
Runtime Complexity: O(n * log(n))
Space Complexity: O(1)

"""


defh_index(citations: list[int]) ->int:
"""
 Return H-index of citations

 >>> h_index([3, 0, 6, 1, 5])
 3
 >>> h_index([1, 3, 1])
 1
 >>> h_index([1, 2, 3])
 2
 >>> h_index('test')
 Traceback (most recent call last):
 ...
 ValueError: The citations should be a list of non negative integers.
 >>> h_index([1,2,'3'])
 Traceback (most recent call last):
 ...
 ValueError: The citations should be a list of non negative integers.
 >>> h_index([1,2,-3])
 Traceback (most recent call last):
 ...
 ValueError: The citations should be a list of non negative integers.
 """

# validate:
ifnotisinstance(citations, list) ornotall(
isinstance(item, int) anditem>=0foritemincitations
 ):
raiseValueError("The citations should be a list of non negative integers.")

citations.sort()
len_citations=len(citations)

foriinrange(len_citations):
ifcitations[len_citations-1-i] <=i:
returni

returnlen_citations


if__name__=="__main__":
importdoctest

doctest.testmod()