diff --git a/DIRECTORY.md b/DIRECTORY.md index 34ce88a4f2ab..f9f4a2ec113a 100644 --- a/DIRECTORY.md +++ b/DIRECTORY.md @@ -695,6 +695,7 @@ * [Gauss Easter](other/gauss_easter.py) * [Graham Scan](other/graham_scan.py) * [Greedy](other/greedy.py) + * [H Index](other/h_index.py) * [Least Recently Used](other/least_recently_used.py) * [Lfu Cache](other/lfu_cache.py) * [Linear Congruential Generator](other/linear_congruential_generator.py) diff --git a/other/h_index.py b/other/h_index.py new file mode 100644 index 000000000000..e91389675b16 --- /dev/null +++ b/other/h_index.py @@ -0,0 +1,71 @@ +""" +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) + +""" + + +def h_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: + if not isinstance(citations, list) or not all( + isinstance(item, int) and item >= 0 for item in citations + ): + raise ValueError("The citations should be a list of non negative integers.") + + citations.sort() + len_citations = len(citations) + + for i in range(len_citations): + if citations[len_citations - 1 - i] <= i: + return i + + return len_citations + + +if __name__ == "__main__": + import doctest + + doctest.testmod()