Explore choices carefully with pruning and state rollback.

DFS, BFS, union-find, and traversal-based reasoning.

Complete Backtracking first

Shortest paths, weighted traversal, and network optimization.

Build optimal answers from linear subproblems.

Reason across grids and multidimensional state.

Choose locally optimal moves that build globally optimal results.

Sort, merge, sweep, and schedule overlapping ranges.

Complete Greedy first

Bit tricks, number insight, coordinate reasoning, and formulas.

Pattern matching, parsing, and efficient string transforms.