AoC 2021: day 7 solutions

2021/solutions/day_07.py

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+"""AOC Day 7"""
+
+import pathlib
+import time
+from collections import defaultdict
+
+TEST_INPUT = """16,1,2,0,4,2,7,1,2,14"""
+
+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
+
+def extract(input_data: str) -> list:
+    """take input data and return the appropriate data structure"""
+    return list(map(int, input_data.split(',')))
+
+def fuel2(crabs: list, mean: int) -> int:
+    fuel_sum = 0
+    for crab in crabs:
+        delta = abs(crab - mean)
+        fuel_sum += (delta * (delta + 1)) // 2
+    
+    return fuel_sum
+
+def part1(entries: list) -> int:
+    """part1 solver take the entries and return the part1 solution"""
+    crabs = sorted(entries)
+    middle_crab = crabs[len(crabs)//2]
+
+    return sum(abs(crab - middle_crab) for crab in crabs)
+
+def part2(entries: list) -> int:
+    """part2 solver take the entries and return the part2 solution"""
+    crabs = sorted(entries)
+    mean = sum(crabs)//len(crabs)
+    
+    return min(fuel2(entries, mean), fuel2(entries, mean+1))
+
+def test_input_day_07():
+    """pytest testing function"""
+    entries = extract(TEST_INPUT)
+    assert part1(entries) == 37
+    assert part2(entries) == 168
+
+def test_bench_day_07(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)
+    entries = extract(input_data)
+    print("Part 1: %d" % part1(entries))
+    print("Part 2: %d" % part2(entries))
+    end_time = time.time()
+    print("Execution time: %f" % (end_time-start_time))
+
+if __name__ == "__main__":
+    main()