Merge Intervals 25 XP Medium

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Given an array of intervals where intervals[i] = [start_i, end_i], merge all overlapping intervals and return the non-overlapping intervals.

intervals = [[1,3],[2,6],[8,10],[15,18]]
# [1,3] and [2,6] overlap → merge to [1,6]
# Output: [[1,6],[8,10],[15,18]]

Algorithm:

Sort intervals by start time
Initialize result with first interval
For each next interval: if it overlaps with last in result (start ≤ last end), merge by extending the end
Otherwise, add as new non-overlapping interval

Time: O(n log n) for sorting. Space: O(n) for result.

📋 Instructions

Implement `merge_intervals(intervals)` that merges overlapping intervals. Test with `[[1,3],[2,6],[8,10],[15,18]]`. Print the result.

Sort by start. Use a result list. For each interval, compare its start with the end of the last interval in result. If overlapping, update the end to max of both ends. Otherwise append.

🧪 Test Cases

Input

merge_intervals([[1,3],[2,6],[8,10],[15,18]])

Expected

[[1, 6], [8, 10], [15, 18]]

Test case 1

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main.py

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Output

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