https://leetcode.com/problems/h-index/
https://leetcode.com/mockinterview/session/result/xjcpjlh/
看了hint,不然的话,可能用的是排序的方法,O(NlgN),现在的方法用了extra space,但是时间复杂度是O(N).
package com.company; import java.util.*; // https://discuss.leetcode.com/topic/32272/share-my-greedy-solution/2 class Solution { public int hIndex(int[] citations) { int[] rec = new int[citations.length]; for (int i=0; i<citations.length; i++) { if (citations[i] >= 1 && citations[i] <= citations.length) { rec[citations[i]-1]++; } else if (citations[i] > citations.length) { rec[citations.length-1]++; } } int count = 0; for (int i=citations.length; i>0; i--) { count += rec[i-1]; if (count >= i) { return i; } } return 0; } } public class Main { public static void main(String[] args) throws InterruptedException { System.out.println("Hello!"); Solution solution = new Solution(); // Your Codec object will be instantiated and called as such: int[] citations = {3, 0, 6, 1, 5}; int ret = solution.hIndex(citations); System.out.printf("ret:%d ", ret); System.out.println(); } }