solves set matrix zeroes

Author: anishLearnsToCode

README.md

@@ -66,6 +66,7 @@
 |  67  | [Add Binary](https://leetcode.com/problems/add-binary)                                                                                                    |                                         [![Java](assets/java.png)](src/AddBinary.java) [![Python](assets/python.png)](python/add_binary.py)                                          |                                                                                                                                   |
 |  69  | [Sqrt(x)](https://leetcode.com/problems/sqrtx)                                                                                                            |                                              [![Java](assets/java.png)](src/Sqrtx.java) [![Python](assets/python.png)](python/sqrt.py)                                               |                                                                                                                                   |
 |  70  | [Climbing Stairs](https://leetcode.com/problems/climbing-stairs)                                                                                          |                                    [![Java](assets/java.png)](src/ClimbingStairs.java) [![Python](assets/python.png)](python/climbing_stairs.py)                                     |                                                                                                                                   |
+|  73  | [Set Matrix Zeroes](https://leetcode.com/problems/set-matrix-zeroes)                                                                                      |                                                                 [![Java](assets/java.png)](src/SetMatrixZeroes.java)                                                                 |                                                                                                                                   |
 |  83  | [Remove Duplicates from Sorted List](https://leetcode.com/problems/remove-duplicates-from-sorted-list)                                                    |                   [![Java](assets/java.png)](src/RemoveDuplicatesFromSortedList.java) [![Python](assets/python.png)](python/remove_duplicates_from_linked_list.py)                   |                                                                                                                                   |
 |  88  | [Merge Sorted Array](https://leetcode.com/problems/merge-sorted-array)                                                                                    |                                  [![Java](assets/java.png)](src/MergeSortedArray.java) [![Python](assets/python.png)](python/merge_sorted_array.py)                                  |                                                                                                                                   |
 |  94  | [Binary Tree Inorder Traversal](https://leetcode.com/problems/binary-tree-inorder-traversal/)                                                             |                       [![Java](assets/java.png)](src/BinaryTreeInorderTraversal.java) [![Python](assets/python.png)](python/binary_tree_inorder_traversal.py)                        |                                                                                                                                   |

src/SetMatrixZeroes.java

@@ -0,0 +1,46 @@
+// https://leetcode.com/problems/set-matrix-zeroes/
+// T: O(m * n)
+// S: O(1)
+
+public class SetMatrixZeroes {
+    public void setZeroes(int[][] matrix) {
+        final int rows = matrix.length, columns = matrix[0].length;
+        boolean firstColumnIsZero = false;
+
+        for (int row = 0 ; row < rows ; row++) {
+            if (matrix[row][0] == 0) firstColumnIsZero = true;
+            for (int column = 1 ; column < columns ; column++) {
+                if (matrix[row][column] == 0) {
+                    matrix[row][0] = 0;
+                    matrix[0][column] = 0;
+                }
+            }
+        }
+
+        for (int column = columns - 1 ; column >= 1 ; column--) {
+            if (matrix[0][column] == 0) {
+                markColumn0(matrix, column);
+            }
+        }
+
+        for (int row = rows - 1 ; row >= 0 ; row--) {
+            if (matrix[row][0] == 0) {
+                markRow0(matrix, row);
+            }
+        }
+
+        if (firstColumnIsZero) markColumn0(matrix, 0);
+    }
+
+    private void markRow0(int[][] matrix, int row) {
+        for (int column = 0 ; column < matrix[0].length ; column++) {
+            matrix[row][column] = 0;
+        }
+    }
+
+    private void markColumn0(int[][] matrix, int column) {
+        for (int row = 0 ; row < matrix.length ; row++) {
+            matrix[row][column] = 0;
+        }
+    }
+}