The O(n) Club: Distinct Subsequences, or How to Skip Letters Like a Pro (and Keep Your Sanity)
The O(n) Club: Distinct Subsequences, or How to Skip Letters Like a Pro (and Keep Your Sanity) ⚡ TL;DR Want the number of ways to get t as a…
The O(n) Club: Valid Parenthesis String — Greedy for Sanity, Wild About Wildcards
The O(n) Club: Valid Parenthesis String — Greedy for Sanity, Wild About Wildcards ⚡ TL;DR This interview classic wants you to check if a…
The O(n) Club: Repeated Substring Pattern—Now With 100% More Magic Rope
The O(n) Club: Repeated Substring Pattern—Now With 100% More Magic Rope ⚡ TL;DR Want to know if your string is secretly “la la la”…
The O(n) Club: Zigzag Conversion – How to Break, Not Break, And Break Your Strings
The O(n) Club: Zigzag Conversion – How to Break, Not Break, And Break Your Strings ⚡ TL;DR Take your input string, sprinkle it…
The O(n) Club: Minimum Remove to Make Valid Parentheses — Java’s Answer to Your Bracket Nightmares
The O(n) Club: Minimum Remove to Make Valid Parentheses — Java’s Answer to Your Bracket Nightmares ⚡ TL;DR Dev nightmare: You have a string…
The O(n) Club: Interleaving String — Your DP Soap Opera Starter Pack
The O(n) Club: Interleaving String — Your DP Soap Opera Starter Pack ⚡ TL;DR Check if s3 is a flawless mashup of s1 and s2, but don’t mess…
The O(n) Club: All the Binary Tree Paths Your Leaves Will Ever Need
The O(n) Club: All the Binary Tree Paths Your Leaves Will Ever Need ⚡ TL;DR You want every root-to-leaf path in a binary tree? Great! DFS is…
The O(n) Club: Remove Duplicate Letters: Stack Attacks and Lex Wins
The O(n) Club: Remove Duplicate Letters—Stack Attacks and Lex Wins ⚡ TL;DR Want one of each letter from your string, perfectly alphabetized?…
The O(n) Club: Wildcard Word Search—Why Brute Force is for Masochists
The O(n) Club: Wildcard Word Search—Why Brute Force is for Masochists ⚡ TL;DR If your plan is ‘dump words in an ArrayList and hope your…
The O(n) Club: Wildcard Matching: How to Outsmart Your Inner Greedy Asterisk
The O(n) Club: Wildcard Matching—How to Outsmart Your Inner Greedy Asterisk ⚡ TL;DR This isn’t regex, it’s chaos—Wildcard Matching…