miguel 1.7 soln

Author: miguelHx

Python/chapter01/1.7 - Rotate Matrix/miguel_1.7_sol.py

@@ -0,0 +1,87 @@
+"""
+Python version 3.7.0
+1.7 - Rotate Matrix
+Given an image represented by an NxN matrix, where each pixel in the image is 4 bytes, write a method to rotate
+the image by 90 degrees.  Can you do this in place?
+"""
+import unittest
+from typing import List, Callable
+
+
+def rotate_matrix(matrix: List[List[int]], N: int) -> List[List[int]]:
+    """
+    Rotate matrix will rotate the given matrix by 90 degrees.
+    Runtime: O(N^2), asymptotic runtime depends on N
+    Space Complexity: O(N^2), creating a new matrix of NxN called 'rotated'
+    :param matrix: an NxN matrix
+    :param N: the size of the matrix (NxN)
+    :return: a newly rotated matrix
+    """
+    rotated = [[0 for i in range(N)] for j in range(N)]
+    for i in range(N):
+        for j in range(N):
+            rotated[j][(N-1)-i] = matrix[i][j]
+    return rotated
+
+
+def rotate_matrix_in_place(matrix: List[List[int]], N: int) -> List[List[int]]:
+    """
+    Does the same as rotate_matrix, but in place.
+    :param matrix: an NxN matrix
+    :param N: the size of the matrix (NxN)
+    :return:
+    """
+    return matrix
+
+
+class TestRotateMatrixFunction(unittest.TestCase):
+    def _run_tests(self, f: Callable[[List[List[int]], int], List[List[int]]]):
+        cases = [
+            (
+                [
+                    [1, 2, 3, 4],
+                    [5, 6, 7, 8],
+                    [9, 10, 11, 12],
+                    [13, 14, 15, 16]
+                ],
+                4,
+                [
+                    [13, 9, 5, 1],
+                    [14, 10, 6, 2],
+                    [15, 11, 7, 3],
+                    [16, 12, 8, 4]
+                ]
+            ),
+            (
+                [
+                    [1, 2, 3],
+                    [4, 5, 6],
+                    [7, 8, 9]
+                ],
+                3,
+                [
+                    [7, 4, 1],
+                    [8, 5, 2],
+                    [9, 6, 3]
+                ]
+            ),
+            (
+                [
+                    [1]
+                ],
+                1,
+                [
+                    [1]
+                ]
+            )
+        ]
+        for matrix, N, expected in cases:
+            self.assertEqual(f(matrix, N), expected, msg=(matrix, N, expected))
+
+    def test_rotate_matrix(self):
+        self._run_tests(rotate_matrix)
+        # self._run_tests(rotate_matrix_in_place)
+
+
+if __name__ == '__main__':
+    unittest.main()