题目
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.”
解题思路
对与第i篇文章，引用次数是c，那么就有n-i篇文章的引用次数>c，找到第一篇引用次数大于等于n-i，找的时候使用二分
代码
class Solution:
def hIndex(self, citations: List[int]) -> int:
n = len(citations)
l, r = 0, n - 1
while l <= r:
mid = (l + r) // 2
if citations[mid] == n - mid:
return n - mid
if citations[mid] > n - mid:
r = mid - 1
else:
l = mid + 1
return n - l
