Algorithms

Race five classic algorithms and watch the bars move.

The halving walk — find 1 in a million with 20 probes.

Classify five functions. Learn to read a loop by shape.

The call stack as a machine — push, pop, repeat.

Pointer-chase primitives: reverse, middle, cycle.

LIFO and FIFO — two sides of the same shape.

Buckets, chains, and probes — predict the final table layout.

Walk a binary search tree four different ways.

Sift up, sift down, and the streaming top-k trick.

Nodes, edges, a queue, a stack — pick a side and walk.

Greedy relaxation over weighted graphs — the OSPF core.

Overlapping subproblems, solved once, cached forever.

Collapse O(n²) brute force into O(n) with two disciplined pointers.

Depth-first search with undo — the shape behind sudoku, n-queens, and every constraint solver.