Merge pull request #96 from MIT-Emerging-Talent/move_zeroes

Move zeroes (Resolves #68)

solutions/move_zeroes.py

@@ -0,0 +1,59 @@
+"""
+A module provides a function to move all zeroes in an array to the end
+while maintaining the relative order of the non-zero elements.
+
+Module contents:
+    move_zeroes(nums): Rearranges the given list in-place as per the described behavior.
+
+Author: Mudassra Taskeen
+Date: 2025-01-08
+"""
+
+from typing import List
+
+
+def move_zeroes(nums: List[int]) -> None:
+    """
+    Move all 0's to the end of the input list in-place while maintaining
+    the relative sequence of non-zero elements.
+
+    Arguments:
+        nums (List[int]): The input list of integers.
+
+    Returns:
+        None: The function modifies the input list in-place.
+
+    Raises:
+        AssertionError: If nums is not a list of integers.
+
+    Examples:
+        >>> nums = [0, 1, 0, 3, 12]
+        >>> move_zeroes(nums)
+        >>> nums
+        [1, 3, 12, 0, 0]
+
+        >>> nums = [0]
+        >>> move_zeroes(nums)
+        >>> nums
+        [0]from typing import list
+
+        >>> nums = [4, 0, 5, 0, 6]
+        >>> move_zeroes(nums)
+        >>> print(nums)
+        [4, 5, 6, 0, 0]
+    """
+
+    # Defensive assertions
+    assert isinstance(nums, list), "Input must be of type List"
+    assert all(isinstance(x, int) for x in nums), (
+        "All elements in the list must be integers"
+    )
+    # Implementation: Two-pointer approach
+
+    non_zero_index = 0
+
+    for i, num in enumerate(nums):
+        if num != 0:
+            nums[non_zero_index], nums[i] = nums[i], nums[non_zero_index]
+
+            non_zero_index += 1

solutions/tests/test_move_zeroes.py

@@ -0,0 +1,96 @@
+"""
+Unit tests for the moveZeroes function.
+Test Categories:
+    - Standard Cases: Various input arrays with different combinations of zeros and non-zeros
+    - Edge Cases: Arrays with only zeros, only non-zeros, or an empty array
+    - Defensive Cases: Invalid input handling
+
+The tests verify that the function:
+    - Correctly moves zeros to the end
+    - Maintains the relative order of non-zero elements
+    - Handles edge cases like empty arrays and arrays with only zeros
+    - Validates input types and conditions
+
+Date: 2025-01-07
+Author: Mudassra Taskeen
+"""
+
+import unittest
+
+from ..move_zeroes import move_zeroes
+
+
+class TestMoveZeroes(unittest.TestCase):
+    """Test cases for move_zeroes function."""
+
+    def test_standard_case(self):
+        """It should move all zeros to the end while maintaining order."""
+        nums = [0, 1, 0, 3, 12]
+        move_zeroes(nums)
+        self.assertEqual(nums, [1, 3, 12, 0, 0])
+
+    def test_single_zero(self):
+        """
+        It should handle a single zero correctly.
+        """
+        nums = [0]
+        move_zeroes(nums)
+        self.assertEqual(nums, [0])
+
+    def test_single_non_zero(self):
+        """
+        It should handle a single non-zero element correctly.
+        """
+        nums = [5]
+        move_zeroes(nums)
+        self.assertEqual(nums, [5])
+
+    def test_all_zeros(self):
+        """
+        It should handle arrays with all zeros.
+        """
+        nums = [0, 0, 0, 0]
+        move_zeroes(nums)
+        self.assertEqual(nums, [0, 0, 0, 0])
+
+    def test_all_non_zeros(self):
+        """
+        It should leave arrays with no zeros unchanged.
+        """
+        nums = [1, 2, 3, 4]
+        move_zeroes(nums)
+        self.assertEqual(nums, [1, 2, 3, 4])
+
+    def test_empty_array(self):
+        """
+        It should handle an empty array.
+        """
+        nums = []
+        move_zeroes(nums)
+        self.assertEqual(nums, [])
+
+    def test_edge_case_with_large_numbers(self):
+        """
+        It should handle large numbers correctly.
+        """
+        nums = [1000000, 0, 999999, 0, 1]
+        move_zeroes(nums)
+        self.assertEqual(nums, [1000000, 999999, 1, 0, 0])
+
+    def test_non_list_input(self):
+        """
+        It should raise AssertionError for non-list input.
+        """
+        with self.assertRaises(AssertionError):
+            move_zeroes(123)
+
+    def test_non_integer_elements(self):
+        """
+        It should raise AssertionError for non-integer elements in the list.
+        """
+        with self.assertRaises(AssertionError):
+            move_zeroes([1, "a", 0])
+
+
+if __name__ == "__main__":
+    unittest.main()