Core Patterns
The handful of moves behind most array and string problems. Learn to spot which one a problem wants.
7 lessons · 215 min
0 of 7 done
Pointers and windows
- LessonTwo PointersTwo fingers on the data, moving with purpose.30 minbeginner
- LessonSliding WindowA frame that slides along; you only update its edges.35 minbeginner
- LessonFast & Slow PointersA hare and a tortoise: if there's a loop, they meet.25 minintermediate
- LessonPrefix SumPrecompute running totals; any range sum is one subtraction.25 minbeginner