Merge pull request #396 from diwas7777/patch-2

Create solution3.py for problem 1

Author: moe18

Problems/1_matrix_times_vector/solution3.py

@@ -0,0 +1,30 @@
+from numpy import dot as dot_product
+
+def matrix_dot_vector(a: list[list[int|float]], b: list[int|float]) -> list[int|float]:
+    if len(a) != len(b):
+        return -1
+
+    return dot_product(a,b)
+
+def test_matrix_dot_vector() -> None:
+    # empty product
+    assert matrix_dot_vector([], []) == []
+
+    # invalid product
+    assert matrix_dot_vector([], [1, 2]) == -1
+    assert matrix_dot_vector([[1, 2]], []) == -1
+    assert matrix_dot_vector([[1, 2], [2, 4]], [1]) == -1
+
+    # valid product
+    a: list[list[int | float]] = [[1, 2], [2, 4]]
+    b: list[int | float] = [1, 2]
+    assert matrix_dot_vector(a, b) == [5, 10]
+    
+    # valid product with rectangular matrix (non-square) -- > if we changed  "for j in range(len(a[i]))" to "for j in range(len(a))" previous tests will pass 
+    a: list[list[int | float]] = [[1, 2, 3], [2, 4, 6]]
+    b: list[int | float] = [1, 2, 3]
+    assert matrix_dot_vector(a, b) == [14, 28]
+
+if __name__ == "__main__":
+    test_matrix_dot_vector()
+    print("All tests passed.")