Leetcode 275: H-Index II (binary search)

leetcode_275b.cpp

#include <iostream>
#include <vector>

using namespace std;

int hIndex(vector<int>& citations) {
    int h=0, len=citations.size();
    int l=0, r=len-1, m=l+(r-l)/2;
    while (l <= r) {
        m = l+(r-l)/2;
        if (citations[m] >= len-m){
            h = len-m;
            r = m-1;  //search left half
        }
        else 
            l = m+1;  //search right half
    }
    return h;
}

int main() {
    vector<int> citations {1}; //{0,1,3,5,6};
    cout << hIndex(citations) << "\n";
    return 0;
}