problem: 0054 spiral matrix

Author: cychiu8

0054 Spiral Matrix/0054 Spiral Matrix.md

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+# 0054. Spiral Matrix
+
+- Difficulty: medium
+- Link: https://leetcode.com/problems/spiral-matrix/
+- Topics: Array-String, Matrix
+
+# Clarification
+
+1. Check the inputs and outputs
+    - INPUT: List[List[int]]
+    - OUTPUT: List[int]
+2. Check the main goal
+    - traversal the matrix in spiral order
+        
+        ```
+        Input: matrix = [[1,2,3],[4,5,6],[7,8,9]]
+        Output: [1,2,3,6,9,8,7,4,5]
+        ```
+        
+        ![Untitled](./Untitled.png)
+        
+
+# Naive Solution
+
+### Thought Process
+
+1. the direction sequence is right → down → left → up
+2. boundary Left, right, top, bottom
+    1. go through and shrink the boundary
+- Implement
+    
+    ```python
+    class Solution:
+           
+        def spiralOrder(self, matrix: List[List[int]]) -> List[int]:
+            """
+    				1. the direction sequence is right → down → left → up
+            2. boundary Left, right, top, bottom
+                - go through and shrink the boundary
+            """
+            
+            result = []
+            
+            left = 0
+            right = len(matrix[0])
+            top = 0
+            bottom = len(matrix)
+            
+            j = top
+            while left < right and top < bottom:
+    
+                #right
+                for i in range(left, right):
+                    result.append(matrix[top][i])
+                top += 1
+    
+                # down
+                for j in range(top, bottom):
+                    result.append(matrix[j][right - 1])
+                right -= 1
+                
+                if not (left < right and top < bottom):
+                    break
+    
+                # left
+                for i in range(right - 1, left -1, -1):
+                    result.append(matrix[bottom - 1][i])
+                bottom -= 1
+    
+                # up
+                for j in range(bottom - 1, top - 1, -1):
+                    result.append(matrix[j][left])
+                left += 1
+                    
+            return result
+    ```
+    
+
+### Complexity
+
+- Time complexity: $O(m*n)$
+- Space complexity:$O(m*n)$
+
+### Problems & Improvement
+
+- 
+
+# Improvement
+
+### Thought Process
+
+1. 
+- Implement
+    
+    ```python
+    
+    ```
+    
+
+### Complexity
+
+- Time complexity:
+- Space complexity:
+
+# Check special cases, check error
+
+- 
+
+# Note
+
+- [Spiral Matrix - Microsoft Interview Question - Leetcode 54](https://www.youtube.com/watch?v=BJnMZNwUk1M)