spiral matrix II medium

Author: weiy

Array/SpiralMatrixII.py

@@ -0,0 +1,115 @@
+"""
+Given a positive integer n, generate a square matrix filled with elements from 1 to n2 in spiral order.
+
+Example:
+
+Input: 3
+Output:
+[
+ [ 1, 2, 3 ],
+ [ 8, 9, 4 ],
+ [ 7, 6, 5 ]
+]
+
+
+想清楚在写。
+
+beat 94%
+
+测试地址：
+https://leetcode.com/problems/spiral-matrix-ii/description/
+
+"""
+class Solution(object):
+        
+    def generateMatrix(self, n):
+        """
+        :type n: int
+        :rtype: List[List[int]]
+        """
+        
+        maps = [[0 for i in range(n)] for j in range(n)]
+        
+        current_value = [i for i in range(1, n*n+1)]
+        current_value.reverse()
+        
+        def makeXY(x, y):
+            # up
+            # down
+            # right
+            # left
+            return [(x, y-1),
+                    (x, y+1),
+                    (x+1, y),
+                    (x-1, y)]
+
+        def right(x, y):
+
+            while 1:
+                if not current_value:
+                    return maps
+                xy = makeXY(x, y)
+                if (y > -1 and x > -1) and (y < n and x < n):
+                    if maps[y][x] == 0:
+                        maps[y][x] = current_value.pop()
+                        y, x = xy[2][1], xy[2][0] 
+                    else:
+                        # down
+                        return down(x-1, y+1)
+                else:
+                    # down
+                    return down(x-1, y+1)
+
+        def down(x, y):
+
+            while 1:
+                if not current_value:
+                    return maps
+                xy = makeXY(x, y)
+                if (y > -1 and x > -1) and (y < n and x < n):
+                    if maps[y][x] == 0:
+                        maps[y][x] = current_value.pop()
+                        y, x = xy[1][1], xy[1][0] 
+
+                    else:
+                        # left
+                        return left(x-1, y-1)
+                else:
+                    # left
+                    return left(x-1, y-1)       
+        def left(x, y):
+
+            while 1:
+                if not current_value:
+                    return maps
+                xy = makeXY(x, y)
+
+                if y > -1 and x > -1 and y < n and x < n:
+                    if maps[y][x] == 0:
+                        maps[y][x] = current_value.pop()
+                        y, x = xy[3][1], xy[3][0] 
+                    else:
+                        # up
+                        return up(x+1, y-1)
+                else:
+                    # up
+                    return up(x+1, y-1)  
+        def up(x, y):
+
+            while 1:
+                if not current_value:
+                    return maps
+                xy = makeXY(x, y)
+                
+                if y > -1 and x > -1 and y < n and x < n:
+                    if maps[y][x] == 0:
+                        maps[y][x] = current_value.pop()
+                        y, x = xy[0][1], xy[0][0] 
+                    else:
+                        # right
+                        return right(x+1, y+1)
+                else:
+                    # right
+                    return right(x+1, y+1)              
+                
+        return right(0, 0)