274. H 指数
274. H 指数
题目
Given an array of integers citations
where citations[i]
is the number of citations a researcher received for their ith
paper, return the researcher 's h-index.
According to the definition of h-index on Wikipedia: The h-index is defined as the maximum value of h
such that the given researcher has published at least h
papers that have each been cited at least h
times.
Example 1:
Input: citations = [3,0,6,1,5]
Output: 3
Explanation: [3,0,6,1,5] 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, their h-index is 3.
Example 2:
Input: citations = [1,3,1]
Output: 1
Constraints:
n == citations.length
1 <= n <= 5000
0 <= citations[i] <= 1000
题目大意
给你一个整数数组 citations
,其中 citations[i]
表示研究者的第 i
篇论文被引用的次数。计算并返回该研究者的 h
指数。
根据维基百科上 h
指数的定义:h
代表“高引用次数” ,一名科研人员的 h
指数 是指他(她)至少发表了 h
篇论文,并且 至少 有 h
篇论文被引用次数大于等于 h
。如果 h
有多种可能的值,h
指数 是其中最大的那个。
示例 1:
输入:citations = [3,0,6,1,5]
输出:3
解释:给定数组表示研究者总共有 5 篇论文,每篇论文相应的被引用了 3, 0, 6, 1, 5 次。
由于研究者有 3 篇论文每篇 至少 被引用了 3 次,其余两篇论文每篇被引用 不多于 3 次,所以她的 h 指数是 3。
示例 2:
输入:citations = [1,3,1]
输出:1
解题思路
- 第一步:排序,将数组由大到小排序;
- 第二步:从左到右遍历数组,如果
citations[i]>i
则说明至少有i+1
篇论文被引用了至少i+1
次;
复杂度分析
- 时间复杂度:
O(nlogn)
- 空间复杂度:
O(1)
代码
/**
* @param {number[]} citations
* @return {number}
*/
var hIndex = function (citations) {
citations.sort((a, b) => b - a);
let res = 0;
while (citations[res] > res) res++;
return res;
};
相关题目
题号 | 标题 | 题解 | 标签 | 难度 |
---|---|---|---|---|
275 | H 指数 II | [✓] | 数组 二分查找 |