A class photo line got shuffled. For each student you know [h, k]: their height h and the number k of students standing in front of them whose height is at least h. Given the shuffled list people, return the original line (front first) as a list of [h, k] pairs. The input always describes a valid line.
Examples
Input: people = [[2, 3], [6, 0], [4, 2], [5, 0], [3, 1]]
Output: [[5, 0], [3, 1], [6, 0], [2, 3], [4, 2]]
Explanation: In front of the 4 stand 5, 3, 6, 2; exactly two of them (5 and 6) are at least 4.
Constraints
0 <= len(people) <= 2000,1 <= h <= 10**6.- Heights may repeat.
- Target complexity: O(n^2) with list insertion is fine.
Goals
- Place tall people first so shorter ones never disturb their counts
- Use the count as an insertion index
- Sort ties so equal heights end up in the right order