275.

H-Index II

Medium

Given an array of integers citations where citations[i] is the number of citations a researcher received for their ith paper and citations is sorted in an ascending order, 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. Example 1: Input: citations = [0,1,3,5,6] Output: 3 Explanation: [0,1,3,5,6] means the researcher has 5 papers in total and each of them had received 0, 1, 3, 5, 6 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 = [1,2,100] Output: 2 Constraints: n == citations.length 1 <= n <= 105 0 <= citations[i] <= 1000 citations is sorted in ascending order. Follow up: Could you solve it in logarithmic time complexity?