Sliding Window
A contiguous range that grows on the right and shrinks on the left — subarray and substring questions in O(n).
This topic is part of Pro.
Free covers the C and Python courses, the first three DSA topics, the opening system design lessons and the beginner AI lessons, all with the full coach. Pro opens the rest of the library in the FollowtheDamnCode app.
What is in it
- 1Fixed-size windowsSlide a window of exactly k items, updating the sum by what enters and what leaves. Pro
- 2The longest valid windowGrow on the right every step; shrink from the left only while the window breaks the rule. Pro
- 3The shortest valid windowGrow until the window satisfies the goal, then shrink while it still does — recording the best each time. Pro
- 4Windows with character countsFind anagrams and permutations inside a string by sliding a fixed window of letter counts. Pro