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."

For example, given citations = [3, 0, 6, 1, 5], which 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, his h-index is 3.

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

解析：

排序分析

代码：

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