《leetcode》:H-Index
2016-07-17 22:17
218 查看
题目
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.
Hint:
An easy approach is to sort the array first.
What are the possible values of h-index?
A faster approach is to use extra space.
思路
借助一个额外的空间tempArr(长度为N+1)来保存数组中各数字出现的次数。tempArr中保存所有大于等于N的数的次数。然后从N—>1开始统计,只要在N篇paper中至少有h篇论文大于等于h,则才返回h。
实现代码如下:
//在N篇paper中至少有h篇论文大于等于h,则才返回h。N篇paper最大值返回N public int hIndex(int[] citations) { if(citations==null||citations.length==0){ return 0; } int len = citations.length; int[] tempArr = new int[len+1]; for(int i=0;i<len;i++){ if(citations[i]>=len){ tempArr[len]++; } else{ tempArr[citations[i]]++; } } int totalNum = 0; for(int i=len;i>=0;i--){ totalNum +=tempArr[i]; if(totalNum>=i){ return i; } } return 0; }
相关文章推荐
- CentOS7安装配置Nexus
- 反射机制的简单使用
- varchar长度需要是2的倍数吗?
- android 打造不同的Seekbar
- spark的submit
- rootkit的检测工具使用(chkrootkit和rootkit hunter)
- android 打造不同的Seekbar
- android 打造不同的Seekbar
- rootkit的检测工具使用(chkrootkit和rootkit hunter)
- 工作第一周 : 适应节奏!
- jstl标签和EL表达式知识点归纳
- Android开发 Java解析Json字符串
- JSP的Model1和Model2架构模式的分析比较
- listview 加载的时候报java.lang.IllegalArgumentException: column ‘_id’ does not exist 错误
- 5个最佳免费Linux杀毒软件
- 5个最佳免费Linux杀毒软件
- Git常见使用方法
- STM32入门之新建工程
- 索引
- python学习——itertools