H-Index II
Given an array of integers citations where citations[i] is the number of citations a researcher received for their i^th paper and citations is sorted in non-descending order, 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.
You must write an algorithm that runs in logarithmic time.
Example 1
Input
citations = [0,1,3,5,6]Output
3The researcher has 5 papers with citations [0, 1, 3, 5, 6], and 3 papers have at least 3 citations each while the remaining two have no more than 3 citations each.
Example 2
Input
citations = [1,2,100]Output
2The researcher has 2 papers with at least 2 citations each, so the h-index is 2.
Constraints
- n == citations.length
- 1 <= n <= 10^5
- 0 <= citations[i] <= 1000
- citations is sorted in ascending order.