Given an array of integers citations where citations[i] is the number of citations a researcher received for their ith paper, return the researcher's h-index.
According to the definition of h-index on Wikipedia: The h-index is defined as the maximum value of h such that the given researcher has published at least h papers that have each been cited at least h times.
Examples
Example 1
Input: citations = [3,0,6,1,5]
Output: 3
Explanation: [3,0,6,1,5] means the researcher has 5 papers in total and each of them had received 3, 0, 6, 1, 5 citations respectively.
Since the researcher has 3 papers with at least 3 citations each and the remaining two with no more than 3 citations each, their h-index is 3.
Example 2
Input: citations = [1,3,1]
Output: 1
Constraints
n == citations.length
1 <= n <= 5000
0 <= citations[i] <= 1000
274. H-Index
Medium
30 Points
Array
Sorting
Counting Sort
Given an array of integers citations where citations[i] is the number of citations a researcher received for their ith paper, return the researcher's h-index.
According to the definition of h-index on Wikipedia: The h-index is defined as the maximum value of h such that the given researcher has published at least h papers that have each been cited at least h times.
Examples
Example 1
Input: citations = [3,0,6,1,5]
Output: 3
Explanation: [3,0,6,1,5] means the researcher has 5 papers in total and each of them had received 3, 0, 6, 1, 5 citations respectively.
Since the researcher has 3 papers with at least 3 citations each and the remaining two with no more than 3 citations each, their h-index is 3.