Interview Classic 150 Questions P274 H-Index

---

Timeline

Timeline

2025-10-03

init

Counting sort

---

Problem:

P274 Hindex

https://leetcode.cn/problems/h-index/description/?envType=study-plan-v2&envId=top-interview-150

After sorting, citations[i] indicates that there are n-i papers with citations greater than or equal to citations[i]. We can simply iterate over h to find the maximum value.

#include <algorithm>
#include <vector>

using std::vector;

class Solution {
    public:
        // A researcher's h-index means that he or she has published at least h papers
        // and at least h papers have been cited at least h times. If h has multiple possible values, the h-index
        // is the largest one.
        int hIndex(vector<int> &citations)
        {
                int n = citations.size();
                int h = 0;

                std::sort(citations.begin(), citations.end());

                for (int i = 1; i <= n; i++) { // Iterate over h
                        if (citations[n - i] >= i) {
                                h = i;
                        }
                }
                return h;
        }
};