Problem

Given an array of integers citations where citations[i] is the number of citations a researcher received for their ith paper, return the researcher’s h-index.

According to the definition of h-index on Wikipedia: The h-index is defined as the maximum value of h such that the given researcher has published at least h papers that have each been cited at least h times.

Example 1:

1
2
3
4
5
Input: citations = [3,0,6,1,5]
Output: 3
Explanation: [3,0,6,1,5] means the researcher has 5 papers in total and each of them had received 3, 0, 6, 1, 5 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, their h-index is 3.

Example 2:

1
2
3
Input: citations = [1,3,1]
Output: 1

Constraints:

  • n == citations.length
  • 1 <= n <= 5000
  • 0 <= citations[i] <= 1000

Solve

1
2
3
4
5
6
7
8
9
10
11
class Solution:
    def hIndex(self, citations: List[int]) -> int:
        nums = sorted(citations)
        n = len(nums)

        for i in range(n):
            if n - i <= nums[i]:
                return n-i
        
        return 0

改enumerate

1
2
3
4
5
6
7
8
9
10
11
class Solution:
    def hIndex(self, citations: List[int]) -> int:
        nums = sorted(citations)
        n = len(nums)

        for i,val in  enumerate(nums):
            if n - i <= val:
                return n-i
        
        return 0