面试经典150题——Day11

一、题目

274. H-Index

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

题目来源：leetcode

二、题解

class Solution {
public:
    int hIndex(vector<int>& citations) {
        int n = citations.size();
        sort(citations.begin(),citations.end());
        int hIndex = 0;
        for(int i = 0;i < n;i++){
            //剩余几篇文章
            int paperNums = n - i;
            //若当前引用值已经大于等于剩余文章数
            if(citations[i] >= paperNums) return paperNums;
            if(paperNums >= citations[i] && citations[i] > hIndex){
                hIndex = citations[i];
            }
        }
        return hIndex;
    }
};