274. H-Index

难度: Medium

题目描述

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:

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:

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

 

Constraints:

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

解题思路

代码实现

解决方案

java

class Solution {
    public int hIndex(int[] citations) {

        Arrays.sort(citations);
        if (citations[0] >= citations.length) {
            return citations.length;
        }

        int h=0;

        for (int i = citations.length-1; i>=0; i--) {
            if(citations[i]>=citations.length-i){
                h = citations.length-i;
            }

        }
        return h;

    }
}