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; } };
