274.h-index.ts

/*
 * @lc app=leetcode id=274 lang=typescript
 *
 * [274] H-Index
 *
 * https://leetcode.com/problems/h-index/description/
 *
 * algorithms
 * Medium (38.44%)
 * Likes:    874
 * Dislikes: 323
 * Total Accepted:    360.1K
 * Total Submissions: 933.8K
 * Testcase Example:  '[3,0,6,1,5]'
 *
 * Given an array of integers citations where citations[i] is the number of
 * citations a researcher received for their i^th 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
 *
 *
 */

// @lc code=start
function hIndex(citations: number[]): number {
  citations.sort((a, b) => b - a);
  let h = 0;
  for (let i = 0; i < citations.length; i++) {
    if (citations[i] >= i + 1) h = i + 1;
    else break;
  }
  return h;
}
// @lc code=end