Matrices

Grids, rotations, spirals and 2-D prefix sums.

28 problems

Status	Title	Tags	Acceptance	Difficulty
	1. Valid Sudoku	Hash Set	—	Medium
	2. Word Search	DFS · Backtracking	—	Medium
	3. Sudoku Solver	Backtracking	—	Hard
	4. Rat in a Maze	Backtracking · DFS	—	Medium
	5. Grid Paths with Obstacles	Dynamic Programming · Grid	—	Medium
	6. Minimum Path Sum	Dynamic Programming · Grid	—	Medium
	7. Largest Square of Ones	Dynamic Programming · Grid	—	Medium
	8. Rotting Oranges	Multi-source BFS	—	Medium
	9. Count Regions of Same Colour	DFS · Flood Fill	—	Easy
	10. Knight's Shortest Path	BFS	—	Medium
	11. Transpose a Matrix	Matrix	—	Easy
	12. Add Two Matrices	Matrix	—	Easy
	13. Multiply Two Matrices	Matrix	—	Medium
	14. Rotate Matrix 90° Clockwise	Matrix	—	Medium
	15. Spiral Order	Simulation	—	Medium
	16. Spiral Matrix Generator	Simulation	—	Medium
	17. Diagonal Difference	Matrix	—	Easy
	18. Row with Maximum Sum	Matrix	—	Easy
	19. Set Matrix Zeroes	Matrix	—	Medium
	20. Search a Sorted Matrix	Staircase Search	—	Medium
	21. Sub-matrix Sum Queries	2-D Prefix Sum	—	Medium
	22. Island Perimeter	Grid	—	Easy
	23. Negatives in a Sorted Matrix	Staircase	—	Easy
	24. Toeplitz Matrix	Matrix	—	Easy
	25. Game of Life — One Step	Simulation	—	Medium
	26. Row with Most Ones	Binary Search	—	Easy
	27. Minesweeper Numbers	Grid	—	Medium
	28. Richest Customer Wealth	Matrix	—	Easy

28 of 28 problems