LeetCode[274] 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.
意思是这个人至多有h篇文章被引用了至少h次
class Solution {
public:
int hIndex(vector<int>& citations) {
sort(citations.begin(), citations.end(), greater<int>());
for (int i = 0; i < citations.size(); i++)
{
if (i >= citations[i])
return i;
}
return citations.size();
}
};