H-index I, II

I. Given an array of citations (each citation was 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 has at least H citations each, and the other n−h papers has no more than H citation S each. "

For example, given citations = [3, 0, 6, 1, 5] , which means the researcher have papers in total and each of 5 them had received 3, 0, 6, 1, 5 Citatio NS respectively. Since the researcher have papers with at least citations each and the remaining both with 3 3 no more than 3 CIT Ations each, he h-index is 3 .

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

Runtime:4ms.

1 classSolution {2  Public:3     intHindex (vector<int>&citations) {4         intn =citations.size ();5         if(n = =0)return 0;6         7         inti =1;8 sort (Citations.begin (), Citations.end ());9          while(I <=N) {Ten              while(Citations[n-i] >=i) Onei++; A             returnI1; -         } -         returncitations[0]; the     } -};

II. Follow up for h-index:what if the citations array was sorted in ascending order? Could you optimize your algorithm?

Runtime:12ms.

1 classSolution {2  Public:3     intHindex (vector<int>&citations) {4         intn =citations.size ();5         if(n = =0)return 0;6         7         intLow =0, high = n-1;8          while(Low <=High ) {9             intMid = (low + high)/2;Ten              One             if(N-mid <=Citations[mid]) AHigh = mid-1; -             Else -Low = mid +1; the         } -         returnN-Low ; -     } -};

H-index I, II