fix:移除元素

14_刷题/problem_solving_03.py

@@ -6,6 +6,12 @@ from typing import List
 
 class Solution:
     def removeElement(self, nums: List[int], val: int) -> int:
+        """
+        左指针 单指针遍历
+        :param nums:
+        :param val:
+        :return:
+        """
         left = 0
         for index in range(0, len(nums)):
             if nums[index] != val:
@@ -13,7 +19,24 @@ class Solution:
                 left += 1
         return left
 
+    def removeElement2(self, nums: List[int], val: int) -> int:
+        """
+        双指针优化,左右夹逼
+        :param nums:
+        :param val:
+        :return:
+        """
+        left = 0
+        right = len(nums)
+        while left < right:
+            if nums[left] == val:
+                nums[left] = nums[right - 1]
+                right -= 1
+            else:
+                left += 1
+        return left
+
 
 if __name__ == '__main__':
-    result = Solution().removeElement([2], 3)
+    result = Solution().removeElement2([2], 3)
     print(result)