54. Spiral Matrix

Author: Tushar Borole

.idea/workspace.xml

@@ -100,6 +100,7 @@
 | 36   | [Valid Sudoku](https://leetcode.com/problems/valid-sudoku/)                                                                                 | [Itterative](valid_sudoku.js)                                                                                 | 68 ms            | 37.7 MB              | Medium     | O(1)            | O(1)             | [:link:](https://leetcode.com/problems/valid-sudoku/solution/)                 |
 | 146  | [ LRU Cache](https://leetcode.com/problems/lru-cache/)                                                                                      | [Map](lru_cache.js)                                                                                           | 216 ms           | 58.8 MB              | Medium     | O(1)            | O(1)             |                                                                                |
 | 152  | [Maximum Product Subarray](https://leetcode.com/problems/maximum-product-subarray/)                                                         | [Dynamic Programming](max_product.js)                                                                         | 60 ms            | 35 MB                | Medium     | O(N)            | O(1)             | [:link:](https://www.youtube.com/watch?v=-rUBh45rugs)                          |
+| 54   | [Spiral Matrix](https://leetcode.com/problems/spiral-matrix/)                                                                               | [spiral_matrix.js](spiral_matrix.js)                                                                          | 56 ms            | 34 MB                | Medium     |                 |                  | [:link:](https://www.youtube.com/watch?v=3joo9yAZVh8&t=187s)                  |
 | 394  | [Decode String](https://leetcode.com/problems/decode-string/)                                                                               | [Decode String](decode_string.js)                                                                             | 68 ms            | 33.7 MB              | Medium     |                 |                  |                                                                                |
 | 340  | [Longest Substring with At Most K Distinct Characters](https://leetcode.com/problems/longest-substring-with-at-most-k-distinct-characters/) | [Sliding Window Approach](k_distinct_characters.js)                                                           | 68 ms            | 37.1 MB              | Hard       | NlogN           |                  | [:link:](https://www.youtube.com/watch?v=MK-NZ4hN7rs&t=1936s)                  |
 | 297  | [Serialize and Deserialize Binary Tree](https://leetcode.com/problems/serialize-and-deserialize-binary-tree/)                               | [DFS Recursion](serialize_and_deserialize_binary_tree.js)                                                     | 80 ms            | 43.6 MB              | Hard       |                 |                  | [:link:](https://www.youtube.com/watch?v=suj1ro8TIVY)                          |

README.md

@@ -0,0 +1,43 @@
+/**
+ * @param {number[][]} matrix
+ * @return {number[]}
+ */
+var spiralOrder = function(matrix) {
+  if (matrix.length === 0) return [];
+  let rowBegin = 0;
+  let rowEnd = matrix.length - 1;
+  let columnBegin = 0;
+  let columnEnd = matrix[0].length - 1;
+  const res = [];
+
+  while (rowBegin <= rowEnd && columnBegin <= columnEnd) {
+    for (let i = columnBegin; i <= columnEnd; i++) {
+      res.push(matrix[rowBegin][i]);
+    }
+    rowBegin++;
+
+    for (let i = rowBegin; i <= rowEnd; i++) {
+      res.push(matrix[i][columnEnd]);
+    }
+    columnEnd--;
+
+    if (rowBegin <= rowEnd) {
+      for (let i = columnEnd; i >= columnBegin; i--) {
+        res.push(matrix[rowEnd][i]);
+      }
+    }
+    rowEnd--;
+
+    if (columnBegin <= columnEnd) {
+      for (let i = rowEnd; i >= rowBegin; i--) {
+        res.push(matrix[i][columnBegin]);
+      }
+    }
+    columnBegin++;
+  }
+
+  return res;
+};
+
+spiralOrder([[1, 2, 3], [4, 5, 6], [7, 8, 9]]); //?
+spiralOrder([[1, 2, 3, 4], [5, 6, 7, 8], [9, 10, 11, 12]]); //?