The O(n) Club: Maximum XOR of Two Numbers in an Array: Ditch Loops, Grab Bits
The O(n) Club: Maximum XOR of Two Numbers in an Array: Ditch Loops, Grab Bits ⚡ TL;DR Find the biggest XOR between any two numbers in an…
The O(n) Club: Roman to Integer — Why Does ‘IX’ Always Betray Me?
The O(n) Club: Roman to Integer — Why Does ‘IX’ Always Betray Me? ⚡ TL;DR Roman numerals aren’t just fancy birthday cake icing—they come…
The O(n) Club: Pairs of Songs With Total Durations Divisible by 60 — Now That’s What I Call Modulo!
The O(n) Club: Pairs of Songs With Total Durations Divisible by 60 — Now That’s What I Call Modulo! ⚡ TL;DR If you want to pair up songs so…
The O(n) Club: Implement Queue Using Stacks — Stacking Your Odds
The O(n) Club: Implement Queue Using Stacks — Stacking Your Odds ⚡ TL;DR Turn two cranky stacks into a well-behaved queue. Only flip stacks…
The O(n) Club: Maximum Profit in Job Scheduling: How Not to Overbook Your Calendar (or Lose Your Mind)
The O(n) Club: Maximum Profit in Job Scheduling – How Not to Overbook Your Calendar (or Lose Your Mind) ⚡ TL;DR You’re given jobs with a…
The O(n) Club: Add Strings — When Java Says ‘No Cheating’, Do This
The O(n) Club: Add Strings — When Java Says ‘No Cheating’, Do This ⚡ TL;DR Add two monster-sized numbers given as strings. You…
The O(n) Club: Russian Doll Envelopes: Where Sorting Actually Makes You Look Smart
The O(n) Club: Russian Doll Envelopes—Where Sorting Actually Makes You Look Smart ⚡ TL;DR Find the most envelopes that fit inside each other,…
The O(n) Club: Russian Doll Envelopes—How to Stuff Smarter, Not Harder
The O(n) Club: Russian Doll Envelopes—How to Stuff Smarter, Not Harder ⚡ TL;DR Goal: Nest as many envelopes (each: width, height) as possible…
The O(n) Club: LFU Cache: How to Get Unpopular Fast (and Still Write O(1) Java)
The O(n) Club: LFU Cache — How to Get Unpopular Fast (and Still Write O(1) Java) ⚡ TL;DR LFU (Least Frequently Used) Cache is basically a…
The O(n) Club: Best Time to Buy and Sell Stock: Because Margins and Caffeine Can Only Do So Much
The O(n) Club: Best Time to Buy and Sell Stock: Because Margins and Caffeine Can Only Do So Much ⚡ TL;DR One shot at glory: buy low, sell…