# Leetcode 275 - H-index II

Note:

• Use binary search to reach log runtime.
• When citations[mid] >= n - mid, mid might be the answer, but our h can be evern bigger, so we should move left with right = mid (Not right = mid - 1 in case we miss our ans.)
• When citations[mid] < n - mid, either citation[mid] is too small or mid is too small, so we should move right by left = mid + 1.
• When the loop stops, the exception is array like [0], we need to check if cs[left] >= n - left.
If not, return 0.

Question:

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.

You must write an algorithm that runs in logarithmic time.

Example:

Code: