README.md

02-Sliding Window & Prefix Sum

Topics Covered

• Sliding Window
• Prefix Sum
• Hash Table
• Two Pointer
• String Manipulation

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Problems List

No.	Problem	Difficulty	Topics	Link
1	Running Sum of 1D Array	Easy	Prefix Sum	Open
2	Pivot Index	Easy	Prefix Sum	Open
3	Range Sum Query	Easy	Prefix Sum	Open
4	Maximum Average Subarray I	Easy	Sliding Window	Open
5	Longest Ones	Easy	Sliding Window	Open
6	Maximum Erasure Value	Easy	Sliding Window, Hash Table	Open
7	Longest Harmonious Subsequence	Easy	Hash Table	Open
8	Count Binary Substrings	Easy	String, Two Pointer	Open
9	Get Equal Substrings Within Budget	Easy	Sliding Window	Open
10	Diet Plan Performance	Easy	Prefix Sum / Sliding Window	Open
11	Longest Turbulent Subarray	Easy	Sliding Window	Open
12	Count Vowel Substrings	Easy	Sliding Window	Open
13	Defuse the Bomb	Easy	Array, Circular	Open
14	Prefix Sum Query	Easy	Prefix Sum	Open
15	Number of Substrings Containing All Three	Easy	Sliding Window	Open
16	Grumpy Bookstore Owner	Easy	Sliding Window	Open
17	Subarray Sum Equals K	Medium	Prefix Sum, Hash Table	Open
18	Continuous Subarray Sum	Medium	Prefix Sum, Modulo	Open
19	Minimum Size Subarray Sum	Medium	Sliding Window, Two Pointer	Open
20	Longest Substring Without Repeating Characters	Medium	Sliding Window, Hash Table	Open
21	Longest Repeating Character Replacement	Medium	Sliding Window	Open
22	Permutation in String	Medium	Sliding Window, Hash Table	Open
23	Find All Anagrams in a String	Medium	Sliding Window, Hash Table	Open
24	Subarrays with K Different Integers	Medium	Sliding Window, Hash Table	Open
25	Minimum Operations to Reduce X to Zero	Medium	Sliding Window, Hash Table	Open
26	Longest Subarray of 1s After Deleting One Element	Medium	Sliding Window	Open
27	Replace the Substring for Balanced String	Medium	Sliding Window	Open
28	Number of Nice Subarrays	Medium	Sliding Window, Hash Table	Open
29	Count Complete Subarrays	Medium	Sliding Window	Open
30	Maximum Size Subarray Sum Equals K	Medium	Prefix Sum, Hash Table	Open
31	Contiguous Array	Medium	Prefix Sum, Hash Table	Open
32	Product of Last K Numbers	Medium	Prefix Product, Design	Open
33	Subarray Divisible by K	Medium	Prefix Sum, Modulo	Open
34	Longest Arithmetic Subsequence	Medium	Dynamic Programming	Open
35	Maximum Sum of Distinct Subarrays	Medium	Sliding Window, Hash Table	Open
36	Count Good Subarrays	Medium	Sliding Window	Open
37	Count Subarrays With Fixed Bounds	Medium	Sliding Window	Open
38	Maximum Score of Good Subarray	Medium	Sliding Window, Stack	Open
39	Count Increasing Subarrays	Medium	Sliding Window	Open
40	Longest Continuous Subarray	Medium	Sliding Window	Open
41	Frequency of Most Frequent Element	Medium	Sliding Window, Hash Table	Open
42	Minimum Window Substring	Hard	Sliding Window, Hash Table	Open
43	Sliding Window Maximum	Hard	Sliding Window, Deque	Open
44	Fruits Into Baskets	Hard	Sliding Window, Hash Table	Open
45	Binary Subarrays With Sum	Hard	Prefix Sum, Hash Table	Open
46	Count Number of Nice Subarrays (Hard)	Hard	Prefix Sum, Hash Table	Open
47	Max Consecutive Ones III	Hard	Sliding Window	Open
48	Minimum Swaps to Group All 1s Together	Hard	Sliding Window	Open
49	Sliding Window Median	Hard	Sliding Window, Heap / Sorted Map	Open

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Important Patterns

Sliding Window

• Maximum Average Subarray I
• Minimum Size Subarray Sum
• Longest Substring Without Repeating Characters
• Permutation in String
• Minimum Window Substring
• Sliding Window Maximum

Prefix Sum

• Running Sum of 1D Array
• Pivot Index
• Subarray Sum Equals K
• Continuous Subarray Sum
• Contiguous Array
• Subarray Divisible by K

Hash Table + Sliding Window

• Longest Substring Without Repeating Characters
• Find All Anagrams in a String
• Subarrays with K Different Integers
• Maximum Sum of Distinct Subarrays

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Notes and links to problem solutions can be added below.