Matrix LeetCode Problems: All 216, With Python Solutions
Every problem in this library that LeetCode tags Matrix — 216 in total, 178 of them with a complete Python solution, a worked example and the time and space complexity of the approach.
- 216 problems
- 32 Easy
- 125 Medium
- 59 Hard
How Matrix problems are solved
A tag names the subject, not the method. These pattern hubs cover the techniques that actually solve Matrix problems — each one explains the approach, gives a Python template and states its complexity.
- Matrix and Grid — Treat a 2-D grid as a graph whose neighbours are the four adjacent cells.
Matrix problems by difficulty
Showing the first 200 of 216 problems. Problems with a complete Python solution are listed first, then by ascending problem number.
Easy (32)
| # | Problem | Difficulty | Topics |
|---|---|---|---|
| 463 | Island Perimeter | Easy | Depth-First Search, Breadth-First Search, Array +1 |
| 566 | Reshape the Matrix | Easy | Array, Matrix, Simulation |
| 661 | Image Smoother | Easy | Array, Matrix |
| 733 | Flood Fill | Easy | Depth-First Search, Breadth-First Search, Array +1 |
| 766 | Toeplitz Matrix | Easy | Array, Matrix |
| 832 | Flipping an Image | Easy | Bit Manipulation, Array, Two Pointers +2 |
| 867 | Transpose Matrix | Easy | Array, Matrix, Simulation |
| 883 | Projection Area of 3D Shapes | Easy | Geometry, Array, Math +1 |
| 892 | Surface Area of 3D Shapes | Easy | Geometry, Array, Math +1 |
| 999 | Available Captures for Rook | Easy | Array, Matrix, Simulation |
| 1030 | Matrix Cells in Distance Order | Easy | Geometry, Array, Math +2 |
| 1260 | Shift 2D Grid | Easy | Array, Matrix, Simulation |
| 1275 | Find Winner on a Tic Tac Toe Game | Easy | Array, Hash Table, Matrix +1 |
| 1337 | The K Weakest Rows in a Matrix | Easy | Array, Binary Search, Matrix +2 |
| 1351 | Count Negative Numbers in a Sorted Matrix | Easy | Array, Binary Search, Matrix |
| 1380 | Lucky Numbers in a Matrix | Easy | Array, Matrix |
| 1572 | Matrix Diagonal Sum | Easy | Array, Matrix |
| 1582 | Special Positions in a Binary Matrix | Easy | Array, Matrix |
| 1672 | Richest Customer Wealth | Easy | Array, Matrix |
| 1886 | Determine Whether Matrix Can Be Obtained By Rotation | Easy | Array, Matrix |
| 2022 | Convert 1D Array Into 2D Array | Easy | Array, Matrix, Simulation |
| 2133 | Check if Every Row and Column Contains All Numbers | Easy | Array, Hash Table, Matrix |
| 2319 | Check if Matrix Is X-Matrix | Easy | Array, Matrix |
| 2373 | Largest Local Values in a Matrix | Easy | Array, Matrix |
| 2500 | Delete Greatest Value in Each Row | Easy | Array, Matrix, Sorting +2 |
| 2614 | Prime In Diagonal | Easy | Array, Math, Matrix +1 |
| 2639 | Find the Width of Columns of a Grid | Easy | Array, Matrix |
| 2643 | Row With Maximum Ones | Easy | Array, Matrix |
| 2923 | Find Champion I | Easy | Array, Matrix |
| 2946 | Matrix Similarity After Cyclic Shifts | Easy | Array, Math, Matrix +1 |
| 2965 | Find Missing and Repeated Values | Easy | Array, Hash Table, Math +1 |
| 422 | Valid Word SquarePremium | Easy | Array, Matrix |
Medium (113)
| # | Problem | Difficulty | Topics |
|---|---|---|---|
| 36 | Valid Sudoku | Medium | Array, Hash Table, Matrix |
| 48 | Rotate Image | Medium | Array, Math, Matrix |
| 54 | Spiral Matrix | Medium | Array, Matrix, Simulation |
| 59 | Spiral Matrix II | Medium | Array, Matrix, Simulation |
| 63 | Unique Paths II | Medium | Array, Dynamic Programming, Matrix |
| 64 | Minimum Path Sum | Medium | Array, Dynamic Programming, Matrix |
| 73 | Set Matrix Zeroes | Medium | Array, Hash Table, Matrix |
| 74 | Search a 2D Matrix | Medium | Array, Binary Search, Matrix |
| 79 | Word Search | Medium | Depth-First Search, Array, String +2 |
| 130 | Surrounded Regions | Medium | Depth-First Search, Breadth-First Search, Union Find +2 |
| 200 | Number of Islands | Medium | Depth-First Search, Breadth-First Search, Union Find +2 |
| 221 | Maximal Square | Medium | Array, Dynamic Programming, Matrix |
| 240 | Search a 2D Matrix II | Medium | Array, Binary Search, Divide and Conquer +1 |
| 289 | Game of Life | Medium | Array, Matrix, Simulation |
| 304 | Range Sum Query 2D - Immutable | Medium | Design, Array, Matrix +1 |
| 378 | Kth Smallest Element in a Sorted Matrix | Medium | Array, Binary Search, Matrix +2 |
| 417 | Pacific Atlantic Water Flow | Medium | Depth-First Search, Breadth-First Search, Array +1 |
| 419 | Battleships in a Board | Medium | Depth-First Search, Array, Matrix |
| 427 | Construct Quad Tree | Medium | Tree, Array, Divide and Conquer +1 |
| 498 | Diagonal Traverse | Medium | Array, Matrix, Simulation |
| 529 | Minesweeper | Medium | Depth-First Search, Breadth-First Search, Array +1 |
| 542 | 01 Matrix | Medium | Breadth-First Search, Array, Dynamic Programming +1 |
| 695 | Max Area of Island | Medium | Depth-First Search, Breadth-First Search, Union Find +2 |
| 794 | Valid Tic-Tac-Toe State | Medium | Array, Matrix |
| 807 | Max Increase to Keep City Skyline | Medium | Greedy, Array, Matrix |
| 835 | Image Overlap | Medium | Array, Matrix |
| 840 | Magic Squares In Grid | Medium | Array, Hash Table, Math +1 |
| 861 | Score After Flipping Matrix | Medium | Greedy, Bit Manipulation, Array +1 |
| 885 | Spiral Matrix III | Medium | Array, Matrix, Simulation |
| 909 | Snakes and Ladders | Medium | Breadth-First Search, Array, Matrix |
| 931 | Minimum Falling Path Sum | Medium | Array, Dynamic Programming, Matrix |
| 934 | Shortest Bridge | Medium | Depth-First Search, Breadth-First Search, Array +1 |
| 959 | Regions Cut By Slashes | Medium | Depth-First Search, Breadth-First Search, Union Find +3 |
| 994 | Rotting Oranges | Medium | Breadth-First Search, Array, Matrix |
| 1020 | Number of Enclaves | Medium | Depth-First Search, Breadth-First Search, Union Find +2 |
| 1034 | Coloring A Border | Medium | Depth-First Search, Breadth-First Search, Array +1 |
| 1072 | Flip Columns For Maximum Number of Equal Rows | Medium | Array, Hash Table, Matrix |
| 1091 | Shortest Path in Binary Matrix | Medium | Breadth-First Search, Array, Matrix |
| 1139 | Largest 1-Bordered Square | Medium | Array, Dynamic Programming, Matrix |
| 1162 | As Far from Land as Possible | Medium | Breadth-First Search, Array, Dynamic Programming +1 |
| 1219 | Path with Maximum Gold | Medium | Array, Backtracking, Matrix |
| 1222 | Queens That Can Attack the King | Medium | Array, Matrix, Simulation |
| 1253 | Reconstruct a 2-Row Binary Matrix | Medium | Greedy, Array, Matrix |
| 1254 | Number of Closed Islands | Medium | Depth-First Search, Breadth-First Search, Union Find +2 |
| 1267 | Count Servers that Communicate | Medium | Depth-First Search, Breadth-First Search, Union Find +3 |
| 1277 | Count Square Submatrices with All Ones | Medium | Array, Dynamic Programming, Matrix |
| 1292 | Maximum Side Length of a Square with Sum Less than or Equal to Threshold | Medium | Array, Binary Search, Matrix +1 |
| 1314 | Matrix Block Sum | Medium | Array, Matrix, Prefix Sum |
| 1329 | Sort the Matrix Diagonally | Medium | Array, Matrix, Sorting |
| 1391 | Check if There is a Valid Path in a Grid | Medium | Depth-First Search, Breadth-First Search, Union Find +2 |
| 1476 | Subrectangle Queries | Medium | Design, Array, Matrix |
| 1504 | Count Submatrices With All Ones | Medium | Stack, Array, Dynamic Programming +2 |
| 1536 | Minimum Swaps to Arrange a Binary Grid | Medium | Greedy, Array, Matrix |
| 1559 | Detect Cycles in 2D Grid | Medium | Depth-First Search, Breadth-First Search, Union Find +2 |
| 1594 | Maximum Non Negative Product in a Matrix | Medium | Array, Dynamic Programming, Matrix |
| 1605 | Find Valid Matrix Given Row and Column Sums | Medium | Greedy, Array, Matrix |
| 1631 | Path With Minimum Effort | Medium | Depth-First Search, Breadth-First Search, Union Find +4 |
| 1706 | Where Will the Ball Fall | Medium | Array, Matrix, Simulation |
| 1727 | Largest Submatrix With Rearrangements | Medium | Greedy, Array, Matrix +1 |
| 1738 | Find Kth Largest XOR Coordinate Value | Medium | Bit Manipulation, Array, Divide and Conquer +5 |
| 1765 | Map of Highest Peak | Medium | Breadth-First Search, Array, Matrix |
| 1861 | Rotating the Box | Medium | Array, Two Pointers, Matrix |
| 1878 | Get Biggest Three Rhombus Sums in a Grid | Medium | Array, Math, Matrix +3 |
| 1895 | Largest Magic Square | Medium | Array, Matrix, Prefix Sum |
| 1901 | Find a Peak Element II | Medium | Array, Binary Search, Matrix |
| 1905 | Count Sub Islands | Medium | Depth-First Search, Breadth-First Search, Union Find +2 |
| 1914 | Cyclically Rotating a Grid | Medium | Array, Matrix, Simulation |
| 1926 | Nearest Exit from Entrance in Maze | Medium | Breadth-First Search, Array, Matrix |
| 1937 | Maximum Number of Points with Cost | Medium | Array, Dynamic Programming, Matrix |
| 1958 | Check if Move is Legal | Medium | Array, Enumeration, Matrix |
| 1975 | Maximum Matrix Sum | Medium | Greedy, Array, Matrix |
| 1981 | Minimize the Difference Between Target and Chosen Elements | Medium | Array, Dynamic Programming, Matrix |
| 1992 | Find All Groups of Farmland | Medium | Depth-First Search, Breadth-First Search, Array +1 |
| 2017 | Grid Game | Medium | Array, Matrix, Prefix Sum |
| 2018 | Check if Word Can Be Placed In Crossword | Medium | Array, Enumeration, Matrix |
| 2033 | Minimum Operations to Make a Uni-Value Grid | Medium | Array, Math, Matrix +1 |
| 2125 | Number of Laser Beams in a Bank | Medium | Array, Math, String +1 |
| 2146 | K Highest Ranked Items Within a Price Range | Medium | Breadth-First Search, Array, Matrix +2 |
| 2245 | Maximum Trailing Zeros in a Cornered Path | Medium | Array, Matrix, Prefix Sum |
| 2257 | Count Unguarded Cells in the Grid | Medium | Array, Matrix, Simulation |
| 2304 | Minimum Path Cost in a Grid | Medium | Array, Dynamic Programming, Matrix |
| 2326 | Spiral Matrix IV | Medium | Array, Linked List, Matrix +1 |
| 2352 | Equal Row and Column Pairs | Medium | Array, Hash Table, Matrix +1 |
| 2397 | Maximum Rows Covered by Columns | Medium | Bit Manipulation, Array, Backtracking +2 |
| 2428 | Maximum Sum of an Hourglass | Medium | Array, Matrix, Prefix Sum |
| 2482 | Difference Between Ones and Zeros in Row and Column | Medium | Array, Matrix, Simulation |
| 2536 | Increment Submatrices by One | Medium | Array, Matrix, Prefix Sum |
| 2545 | Sort the Students by Their Kth Score | Medium | Array, Matrix, Sorting |
| 2556 | Disconnect Path in a Binary Matrix by at Most One Flip | Medium | Depth-First Search, Breadth-First Search, Array +2 |
| 2596 | Check Knight Tour Configuration | Medium | Depth-First Search, Breadth-First Search, Array +2 |
| 2658 | Maximum Number of Fish in a Grid | Medium | Depth-First Search, Breadth-First Search, Union Find +2 |
| 2661 | First Completely Painted Row or Column | Medium | Array, Hash Table, Matrix |
| 2679 | Sum in a Matrix | Medium | Array, Matrix, Sorting +2 |
| 2684 | Maximum Number of Moves in a Grid | Medium | Array, Dynamic Programming, Matrix |
| 2711 | Difference of Number of Distinct Values on Diagonals | Medium | Array, Hash Table, Matrix |
| 2812 | Find the Safest Path in a Grid | Medium | Breadth-First Search, Union Find, Array +3 |
| 2850 | Minimum Moves to Spread Stones Over Grid | Medium | Breadth-First Search, Array, Dynamic Programming +1 |
| 2906 | Construct Product Matrix | Medium | Array, Matrix, Prefix Sum |
| 286 | Walls and GatesPremium | Medium | Breadth-First Search, Array, Matrix |
| 308 | Range Sum Query 2D - MutablePremium | Medium | Design, Binary Indexed Tree, Segment Tree +2 |
| 311 | Sparse Matrix MultiplicationPremium | Medium | Array, Hash Table, Matrix |
| 348 | Design Tic-Tac-ToePremium | Medium | Design, Array, Hash Table +2 |
| 361 | Bomb EnemyPremium | Medium | Array, Dynamic Programming, Matrix |
| 490 | The MazePremium | Medium | Depth-First Search, Breadth-First Search, Array +1 |
| 505 | The Maze IIPremium | Medium | Depth-First Search, Breadth-First Search, Graph +4 |
| 531 | Lonely Pixel IPremium | Medium | Array, Hash Table, Matrix |
| 533 | Lonely Pixel IIPremium | Medium | Array, Hash Table, Matrix |
| 562 | Longest Line of Consecutive One in MatrixPremium | Medium | Array, Dynamic Programming, Matrix |
| 723 | Candy CrushPremium | Medium | Array, Two Pointers, Matrix +1 |
| 750 | Number Of Corner RectanglesPremium | Medium | Array, Math, Dynamic Programming +1 |
| 1102 | Path With Maximum Minimum ValuePremium | Medium | Depth-First Search, Breadth-First Search, Union Find +4 |
| 1198 | Find Smallest Common Element in All RowsPremium | Medium | Array, Hash Table, Binary Search +2 |
| 1428 | Leftmost Column with at Least a OnePremium | Medium | Array, Binary Search, Interactive +1 |
Hard (55)
| # | Problem | Difficulty | Topics |
|---|---|---|---|
| 37 | Sudoku Solver | Hard | Array, Hash Table, Backtracking +1 |
| 85 | Maximal Rectangle | Hard | Stack, Array, Dynamic Programming +2 |
| 174 | Dungeon Game | Hard | Array, Dynamic Programming, Matrix |
| 212 | Word Search II | Hard | Trie, Array, String +2 |
| 329 | Longest Increasing Path in a Matrix | Hard | Depth-First Search, Breadth-First Search, Graph +5 |
| 363 | Max Sum of Rectangle No Larger Than K | Hard | Array, Binary Search, Matrix +2 |
| 407 | Trapping Rain Water II | Hard | Breadth-First Search, Array, Matrix +1 |
| 675 | Cut Off Trees for Golf Event | Hard | Breadth-First Search, Array, Matrix +1 |
| 741 | Cherry Pickup | Hard | Array, Dynamic Programming, Matrix |
| 749 | Contain Virus | Hard | Depth-First Search, Breadth-First Search, Array +2 |
| 773 | Sliding Puzzle | Hard | Breadth-First Search, Memoization, Array +3 |
| 778 | Swim in Rising Water | Hard | Depth-First Search, Breadth-First Search, Union Find +4 |
| 782 | Transform to Chessboard | Hard | Bit Manipulation, Array, Math +1 |
| 803 | Bricks Falling When Hit | Hard | Union Find, Array, Matrix |
| 827 | Making A Large Island | Hard | Depth-First Search, Breadth-First Search, Union Find +2 |
| 864 | Shortest Path to Get All Keys | Hard | Bit Manipulation, Breadth-First Search, Array +1 |
| 980 | Unique Paths III | Hard | Bit Manipulation, Array, Backtracking +1 |
| 1074 | Number of Submatrices That Sum to Target | Hard | Array, Hash Table, Matrix +1 |
| 1210 | Minimum Moves to Reach Target with Rotations | Hard | Breadth-First Search, Array, Matrix |
| 1263 | Minimum Moves to Move a Box to Their Target Location | Hard | Breadth-First Search, Array, Matrix +1 |
| 1284 | Minimum Number of Flips to Convert Binary Matrix to Zero Matrix | Hard | Bit Manipulation, Breadth-First Search, Array +2 |
| 1289 | Minimum Falling Path Sum II | Hard | Array, Dynamic Programming, Matrix |
| 1293 | Shortest Path in a Grid with Obstacles Elimination | Hard | Breadth-First Search, Array, Matrix |
| 1301 | Number of Paths with Max Score | Hard | Array, Dynamic Programming, Matrix |
| 1349 | Maximum Students Taking Exam | Hard | Bit Manipulation, Array, Dynamic Programming +2 |
| 1368 | Minimum Cost to Make at Least One Valid Path in a Grid | Hard | Breadth-First Search, Graph, Array +3 |
| 1439 | Find the Kth Smallest Sum of a Matrix With Sorted Rows | Hard | Array, Binary Search, Matrix +1 |
| 1444 | Number of Ways of Cutting a Pizza | Hard | Memoization, Array, Dynamic Programming +2 |
| 1463 | Cherry Pickup II | Hard | Array, Dynamic Programming, Matrix |
| 1568 | Minimum Number of Days to Disconnect Island | Hard | Depth-First Search, Breadth-First Search, Array +2 |
| 1595 | Minimum Cost to Connect Two Groups of Points | Hard | Bit Manipulation, Array, Dynamic Programming +2 |
| 1632 | Rank Transform of a Matrix | Hard | Union Find, Graph, Topological Sort +3 |
| 1728 | Cat and Mouse II | Hard | Graph, Topological Sort, Memoization +5 |
| 1970 | Last Day Where You Can Still Cross | Hard | Depth-First Search, Breadth-First Search, Union Find +3 |
| 2088 | Count Fertile Pyramids in a Land | Hard | Array, Dynamic Programming, Matrix |
| 2132 | Stamping the Grid | Hard | Greedy, Array, Matrix +1 |
| 2258 | Escape the Spreading Fire | Hard | Breadth-First Search, Array, Binary Search +1 |
| 2267 | Check if There Is a Valid Parentheses String Path | Hard | Array, Dynamic Programming, Matrix |
| 2290 | Minimum Obstacle Removal to Reach Corner | Hard | Breadth-First Search, Graph, Array +3 |
| 2328 | Number of Increasing Paths in a Grid | Hard | Depth-First Search, Breadth-First Search, Graph +5 |
| 2392 | Build a Matrix With Conditions | Hard | Graph, Topological Sort, Array +1 |
| 2435 | Paths in Matrix Whose Sum Is Divisible by K | Hard | Array, Dynamic Programming, Matrix |
| 2503 | Maximum Number of Points From Grid Queries | Hard | Breadth-First Search, Union Find, Array +4 |
| 2573 | Find the String with LCP | Hard | Greedy, Union Find, Array +3 |
| 2577 | Minimum Time to Visit a Cell In a Grid | Hard | Breadth-First Search, Graph, Array +3 |
| 2617 | Minimum Number of Visited Cells in a Grid | Hard | Stack, Breadth-First Search, Union Find +5 |
| 2713 | Maximum Strictly Increasing Cells in a Matrix | Hard | Memoization, Array, Hash Table +5 |
| 2732 | Find a Good Subset of the Matrix | Hard | Bit Manipulation, Array, Hash Table +1 |
| 2931 | Maximum Spending After Buying Items | Hard | Greedy, Array, Matrix +2 |
| 296 | Best Meeting PointPremium | Hard | Array, Math, Matrix +1 |
| 302 | Smallest Rectangle Enclosing Black PixelsPremium | Hard | Depth-First Search, Breadth-First Search, Array +2 |
| 317 | Shortest Distance from All BuildingsPremium | Hard | Breadth-First Search, Array, Matrix |
| 499 | The Maze IIIPremium | Hard | Depth-First Search, Breadth-First Search, Graph +5 |
| 568 | Maximum Vacation DaysPremium | Hard | Array, Dynamic Programming, Matrix |
| 631 | Design Excel Sum FormulaPremium | Hard | Graph, Design, Topological Sort +4 |
Keep exploring
All LeetCode topicsEvery tag with a page of its own, with the number of problems behind each.LeetCode patternsThe techniques themselves, with a Python template and complexity for each.Curated study listsBlind 75, NeetCode 150 and three more, grouped by pattern.Easy problemsStart here when the data structure is new rather than the problem.
Other topics
- Array1,569
- String672
- Hash Table588
- Math485
- Dynamic Programming481
- Sorting392
- Greedy346
- Depth-First Search289
- Binary Search253
- Database249
- Tree225
- Breadth-First Search223
- Two Pointers201
- Bit Manipulation194
- Binary Tree174
- Heap (Priority Queue)163
- Prefix Sum157
- Stack157
- Simulation144
- Graph138
- Counting126
- Design122
- Sliding Window116
- Backtracking105
When the Matrix problem arrives live
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