Day 7 done!

Author: mo-philrelton

2024/day_07/Python/operators.py

@@ -0,0 +1,66 @@
+import operator as op
+import itertools
+
+def load_input(filename: str) -> list:
+    with open(filename, "r") as file:
+        lines = file.readlines()
+    return [line.strip() for line in lines]
+
+
+def process_input(lines):
+    answers = []
+    values = []
+    for line in lines:
+        _answer, _values = line.split(": ")
+        answers.append(int(_answer))
+        values.append([int(x) for x in _values.split(" ")])
+
+    return answers, values
+
+def check_equation(answer, values, pos_operators = [op.add, op.mul]):
+    Noperators = len(values) - 1
+
+    operator_list = itertools.product(pos_operators, repeat=Noperators)
+
+    for op_list in operator_list:
+        result = values[0]
+        for op, val in zip(op_list, values[1:]):
+            result = op(result, val)
+        if result == answer:
+            return True
+
+def concatenate_operator(a, b):
+    return int(str(a) + str(b))
+
+
+def do_puzzle(answer, values, pos_operators):
+    # Find which equations are possible
+    possible = []
+    for answer, value in zip(answers, values):
+        if check_equation(answer, value, pos_operators=pos_operators):
+            possible.append(True)
+        else:
+            possible.append(False)
+
+    # Sum possible answers
+    total = 0
+    for answer, value, is_possible in zip(answers, values, possible):
+        if is_possible:
+            total += answer
+    print(f"Total possible answers: {total}")
+
+
+if __name__ == "__main__":
+    input_lines = load_input("day07_input.txt")
+
+    answers, values = process_input(input_lines)
+
+    # Part 1:
+    print("Answer Part 1:")
+    pos_operators = [op.add, op.mul]
+    do_puzzle(answers, values, pos_operators)
+
+    # Part 2:
+    print("Answer Part 2:")
+    pos_operators = [op.add, op.mul, concatenate_operator]
+    do_puzzle(answers, values, pos_operators)