class Solution {
    public int hIndex(int[] citations) {
        // sorting the citations in ascending order
        Arrays.sort(citations);
        
        // finding h-index by linear search
        int i = 0;
        while (i < citations.length && citations[citations.length - 1 - i] > i) {
            i++;
        }
        
        return i; // after the while loop, i = i' + 1
    }
}