275. H Index II (Medium) - TengnanYao/daily_leetcode GitHub Wiki

class Solution(object):
    def hIndex(self, citations):
        """
        :type citations: List[int]
        :rtype: int
        """
        # binary search
        n = len(citations)
        l, r = 1, n
        result = 0
        while l <= r:
            m = (l + r) // 2
            if citations[n - m] >= m:
                result = max(result, m)
                l = m + 1
            else:
                r = m - 1
        return result
        
        # brute force
        n = len(citations)
        for i in range(n, 0, -1):
            if citations[n - i] >= i:
                return i
        return 0