## 题目

Given an array of citations (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:

1 | Input: citations = [3,0,6,1,5] |

**Note:**

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

## 思路

Binary Search.

## 代码

1 | class Solution(object): |