Topic 6 Intervals

🛠 Overview

Intervals problems on LeetCode involve working with ranges of values, typically represented as pairs of numbers [start, end]. These problems often require operations like merging, inserting, or determining overlaps between intervals. Understanding these problems is crucial for mastering algorithmic concepts in sorting, greedy algorithms, and binary search.

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🎯 Common Operations on Intervals

• Merging Overlapping Intervals

• Inserting Intervals

• Checking Overlap

• Counting Non-Overlapping Intervals

🧠 Tips and Tricks

1. Sorting is Key:

   • Many interval problems require sorting by the start (or end) of intervals. Sorting simplifies comparisons and merging.

2. Greedy Algorithms Work Well:

   • Problems involving overlapping intervals often use a greedy approach, focusing on choosing the "best" interval at each step.

3. Edge Cases to Watch For:

   • Empty interval lists.

   • Single intervals.

   • Completely overlapping intervals, e.g., [1, 10] and [2, 5].

   • Non-overlapping intervals, e.g., [1, 2] and [3, 4].

4. Understand the Mathematical Overlap Condition:

   • Two intervals overlap if max(start1, start2) <= min(end1, end2).

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🔥 Popular LeetCode Problems on Intervals

1. Summary RangesRanges

2. Merge Intervals

3. Insert Interval

4. Minimum Number of Arrows to Burst Balloons

Happy Coding