feat: spiral-matrix

Author: junbinding

Diff for: arr.spiral-matrix.py

@@ -0,0 +1,62 @@
+from typing import List
+
+class Solution:
+    """
+    54. 螺旋矩阵
+    https://leetcode-cn.com/problems/spiral-matrix/
+    给定一个包含 m x n 个元素的矩阵（m 行, n 列），请按照顺时针螺旋顺序，返回矩阵中的所有元素。
+    """
+    def spiralOrder(self, matrix: List[List[int]]) -> List[int]:
+        result = []
+        if len(matrix) == 0:
+            return result
+
+        left, right, up, down = 0, len(matrix[0]) - 1, 0, len(matrix) - 1
+
+        x, y = 0, 0
+        while left <= right and up <= down:
+            # 向右移动
+            y = left
+            while y <= right and self.avoid(left, right, up, down):
+                result.append(matrix[x][y])
+                y += 1
+            y -= 1
+            up += 1
+
+            # 向下移动
+            x = up
+            while x <= down and self.avoid(left, right, up, down):
+                result.append(matrix[x][y])
+                x += 1
+            x -= 1
+            right -= 1
+
+            # 向左移动
+            y = right
+            while y >= left and self.avoid(left, right, up, down):
+                result.append(matrix[x][y])
+                y -= 1
+            y += 1
+            down -= 1
+
+            # 向上移动
+            x = down
+            while x >= up and self.avoid(left, right, up, down):
+                result.append(matrix[x][y])
+                x -= 1
+            x += 1
+            left += 1
+        return result
+
+    def avoid(self, left, right, up, down):
+        return left <= right and up <= down
+
+
+so = Solution()
+# [1,2,3,6,9,8,7,4,5]
+print(so.spiralOrder([
+ [ 1, 2, 3 ],
+ [ 4, 5, 6 ],
+ [ 7, 8, 9 ]
+]))
+

Diff for: bs.find-minimum-in-rotated-sorted-array-ii.py

@@ -15,9 +15,9 @@ def findMin(self, nums: List[int]) -> int:
         while l < r:
             mid = l + (r - l) // 2
             # 左侧是单调的，旋转发生在右侧
-            if nums[r] < nums[mid]:
+            if nums[mid] > nums[r]:
                 l = mid + 1
-            elif nums[r] > nums[mid]:
+            elif nums[mid] < nums[r]:
                 r = mid
             else:
                 r -= 1