H-Index

 

H-Index

Given an array of citations (each citation is a non-negative integer) of a researcher, write a function to compute the researcher's h-index.

According to the definition of h-index on Wikipedia: "A scientist has index h if h of his/her N papers have at least h citations each, and the other N − h papers have no more than h citations each."

Example:

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, her h-index is 3.

Note: If there are several possible values for h, the maximum one is taken as the h-index.

 

 

 class Solution {
public:
    int hIndex(vector<int>& citations)
    {
        if(citations.size()==0)return 0;
        if(citations.size()==1)return citations[0]!=0;
        sort(citations.begin(),citations.end());
        int i;
         for( i=0;i<citations.size();++i)
             if(citations[i]>=citations.size()-i)
             {
                 break;
             }
        return citations.size()-i;
        
    }
};