AoC 2015: day3

Signed-off-by: Ettore Dreucci <ettore.dreucci@gmail.com>

2015-python/solutions/day_3.py

@@ -0,0 +1,69 @@
+"""AOC 2015 Day 3"""
+
+import pathlib
+import time
+
+TEST_INPUT = """^v^v^v^v^v"""
+
+def read_input(input_path: str) -> str:
+    """take input file path and return a str with the file's content"""
+    with open(input_path, 'r') as input_file:
+        input_data = input_file.read().strip()
+        return input_data
+
+moves = {
+    '^': (0, 1),
+    'v': (0, -1),
+    '>': (1, 0),
+    '<': (-1, 0),
+}
+
+def part1(entries: str) -> int:
+    """part1 solver take a str and return an int"""
+    houses = {(0, 0): 1}
+    pos_x, pos_y = 0, 0
+    for direction in entries:
+        delta_x, delta_y = moves[direction]
+        pos_x += delta_x
+        pos_y += delta_y
+        houses[(pos_x, pos_y)] = houses.get((pos_x, pos_y), 0) + 1
+    return len(houses)
+
+def part2(entries: str) -> int:
+    """part2 solver take a str and return an int"""
+    houses = {(0, 0): 2}
+    pos_x_santa, pos_y_santa = 0, 0
+    pos_x_robot, pos_y_robot = 0, 0
+    for index, direction in enumerate(entries):
+        delta_x, delta_y = moves[direction]
+        if index%2 == 0:
+            pos_x_santa += delta_x
+            pos_y_santa += delta_y
+            houses[(pos_x_santa, pos_y_santa)] = houses.get((pos_x_santa, pos_y_santa), 0) + 1
+        else:
+            pos_x_robot += delta_x
+            pos_y_robot += delta_y
+            houses[(pos_x_robot, pos_y_robot)] = houses.get((pos_x_robot, pos_y_robot), 0) + 1
+    return len(houses)
+
+def test_input_day_2():
+    """pytest testing function"""
+    assert part1(TEST_INPUT) == 2
+    assert part2(TEST_INPUT) == 11
+
+def test_bench_day_2(benchmark):
+    """pytest-benchmark function"""
+    benchmark(main)
+
+def main():
+    """main function"""
+    input_path = str(pathlib.Path(__file__).resolve().parent.parent) + "/inputs/" + str(pathlib.Path(__file__).stem)
+    start_time = time.time()
+    input_data = read_input(input_path)
+    print("Part 1: %d" % part1(input_data))
+    print("Part 2: %d" % part2(input_data))
+    end_time = time.time()
+    print("Execution time: %f" % (end_time-start_time))
+
+if __name__ == "__main__":
+    main()