D. J.:

- Added leetcode problem and solution for 27. Remove Element

Author: nobodyPerfecZ

awesome_python_leetcode/_27_remove_element.py

@@ -0,0 +1,27 @@
+from typing import List
+
+
+class Solution:
+    def removeElement(self, nums: List[int], val: int) -> int:
+        """
+        Given an integer array nums and an integer val, remove all occurrences of val in nums in-place.
+        The order of the elements may be changed. Then return the number of elements in nums which are not equal to val.
+
+        Consider the number of elements in nums which are not equal to val be k, to get accepted, you need to do the following things:
+        - Change the array nums such that the first k elements of nums contain the elements which are not equal to val.
+        The remaining elements of nums are not important as well as the size of nums.
+        - Return k.
+        """
+        left, right, length = 0, len(nums) - 1, 0
+        while left <= right:
+            if nums[right] == val:
+                right -= 1
+            elif nums[left] == val:
+                nums[left], nums[right] = nums[right], nums[left]
+                left += 1
+                right -= 1
+                length += 1
+            else:
+                left += 1
+                length += 1
+        return length

tests/test_27_remove_element.py

@@ -0,0 +1,17 @@
+from typing import List
+
+import pytest
+
+from awesome_python_leetcode._27_remove_element import Solution
+
+
+@pytest.mark.parametrize(
+    argnames=["nums", "val", "expected"],
+    argvalues=[
+        ([3, 2, 2, 3], 3, [2, 2]),
+        ([0, 1, 2, 2, 3, 0, 4, 2], 2, [0, 1, 4, 0, 3]),
+    ],
+)
+def test_func(nums: List[int], val: int, expected: List[int]):
+    length = Solution().removeElement(nums, val)
+    assert nums[:length] == expected