dsa1 min read
Continuous Subarray Sum [Medium] — Prefix Modulo Map
Check if a continuous subarray of length >= 2 sums to a multiple of k using prefix sum modulo k with a HashMap.
Read →
All Posts
1575 articles
dsa1 min read
Longest Consecutive Sequence [Medium] — HashSet O(n)
Find the longest consecutive integer sequence in O(n) by using a HashSet and only starting sequences from their minimum element.
Read →
dsa2 min read
Insert Delete GetRandom O(1) [Medium] — Array + HashMap Design
Design a set with O(1) insert, delete, and getRandom using a dynamic array combined with a HashMap for index tracking.
Read →
dsa2 min read
Find All Anagrams in a String [Medium] — Fixed Window + Freq Match
Find all starting indices of anagram substrings by using a fixed window with character frequency comparison.
Read →
dsa1 min read
Random Pick with Weight [Medium] — Prefix Sum + Binary Search
Implement weighted random selection by building a prefix sum array and using binary search to find the sampled index.
Read →
Page 120 of 315