TikTok VO 面试真题解析：区间合并（Merge Intervals）

Merge Intervals

Given an array intervals representing a collection of intervals, where each interval is intervals[i] = [start, end], write a function to merge all overlapping intervals and return an array of the non-overlapping intervals that cover all the intervals in the input.

Example:

Input: intervals = [[1,3],[2,6],[8,10]]
Output: [[1,6],[8,10]]
Explanation: The intervals [1,3] and [2,6] overlap, so they are merged into [1,6].

Input: intervals = [[1,4],[4,5]]
Output: [[1,5]]

这道题是经典的区间合并问题。做法通常是先按照区间起点排序，然后遍历每个区间，维护当前合并后的最后一个区间：如果下一个区间与它重叠，就更新右边界为更大的结束值；如果不重叠，就把当前区间加入结果并切换到新的区间。核心数据结构是数组，关键思想是排序后线性扫描，时间复杂度为 O(n log n)，空间复杂度通常为 O(n)（不计排序实现）。