Description

Submission

class Solution {
public:
    int hIndex(vector<int>& citations) {
        int n = citations.size();
        sort(citations.begin(), citations.end());
        int lower = 0, upper = n;

        while(lower < upper) {
            int mid = lower + (upper - lower) / 2;  // h-index guess

            if(n - 1 >= mid && citations[n - 1 - mid] > mid) {
                lower = mid + 1;
            } else {
                upper = mid;
            }

        }

        return lower;
    }
};

// 3,0,6,1,5
//    mid  n
// 0 1 3 5 6

// 0 1 2
// 1 1 3