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.
题目大意:给一个数组,是一个科学家各个paper的引用数,求最大的hindex,hindex就是有h篇不低于h引用的paper。
解题思路:首先排个序,然后倒序走一遍更新res就可以了。
public int hIndex(int[] array) { if (array == null || array.length == 0) { return 0; } Arrays.sort(array); int len = array.length; int pos = len - 1; int res = 0; while (pos >= 0) { int tmp = Math.min(len-pos,array[pos]); res = Math.max(res, tmp); pos--; } return res; }