# Day 18 of June LeetCode Challenge

Given an array of citations **sorted in ascending order **(each citation is a non-negative integer) of a researcher, write a function to compute the researcher’s h-index.

According to the definition of h-index on Wikipedia: “A scientist has index *h* if *h* of his/her *N* papers have **at least** *h* citations each, and the other *N − h* papers have **no more than** *h *citations each.”

**Example:**

**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, her h-index is 3.

**Note:**

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

**Follow up:**

- This is a follow up problem to H-Index, where
`citations`

is now guaranteed to be sorted in ascending order. - Could you solve it in logarithmic time complexity?