solves search a 2d matrix

Author: anishLearnsToCode

README.md

@@ -68,6 +68,7 @@
 |  70  | [Climbing Stairs](https://leetcode.com/problems/climbing-stairs)                                                                                          |                                    [![Java](assets/java.png)](src/ClimbingStairs.java) [![Python](assets/python.png)](python/climbing_stairs.py)                                     |                                                                                                                                   |
 |  71  | [Simplify Path](https://leetcode.com/problems/simplify-path)                                                                                              |                                                                  [![Java](assets/java.png)](src/SimplifyPath.java)                                                                   |                                                                                                                                   |
 |  73  | [Set Matrix Zeroes](https://leetcode.com/problems/set-matrix-zeroes)                                                                                      |                                                                 [![Java](assets/java.png)](src/SetMatrixZeroes.java)                                                                 |                                                                                                                                   |
+|  74  | [Search a 2D Matrix](https://leetcode.com/problems/search-a-2d-matrix)                                                                                    |                                                                 [![Java](assets/java.png)](src/SearchA2DMatrix.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/SearchA2DMatrix.java

@@ -0,0 +1,17 @@
+// https://leetcode.com/problems/search-a-2d-matrix
+// T: O(log(m*n))
+// S: O(1)
+
+public class SearchA2DMatrix {
+    public boolean searchMatrix(int[][] matrix, int target) {
+        final int rows = matrix.length, columns = matrix[0].length;
+        int left = 0, right = rows * columns - 1, middle;
+        while (left <= right) {
+            middle = left + (right - left) / 2;
+            if (matrix[middle / columns][middle % columns] == target) return true;
+            else if (matrix[middle / columns][middle % columns] > target) right = middle - 1;
+            else left = middle + 1;
+        }
+        return false;
+    }
+}