solve day 7 part 2, but with brute force

day_07/program.py

@@ -1,15 +1,73 @@
 #!/usr/bin/env python3
 
-# https://adventofcode.com/2024/day/
+# https://adventofcode.com/2024/day/7
 
 def get_lines(filename: str) -> list:
     with open(filename, "r") as file:
         return [line.strip() for line in file.readlines()]
 
 
+def parse_line(line: str) -> tuple:
+    value_str, right_side_str = line.split(": ")
+    value = int(value_str)
+    right_side = [int(i) for i in right_side_str.split()]
+    return value, right_side
+
+
+def num_to_pattern(i: int, base: int, exponent: int) -> str:
+    if i == 0:
+        return "0".zfill(exponent)
+    nums = []
+    while i:
+        i, r = divmod(i, base)
+        nums.append(str(r))
+    return "".join(reversed(nums)).zfill(exponent)
+
+
+def calculate_equation(right_side: list, pattern: str, operators: list) -> int:
+    value = right_side[0]
+    for i, op_str in enumerate(pattern):
+        op = operators[int(op_str)]
+        if op == "*":
+            value *= right_side[i + 1]
+        elif op == "+":
+            value += right_side[i + 1]
+        elif op == "|":
+            value = int(str(value) + str(right_side[i + 1]))
+        else:
+            raise NotImplementedError
+    return value
+
+
+def check_validity(left_value: int, right_side: list, operators: list) -> bool:
+    base = len(operators)
+    exponent = len(right_side) - 1
+    for i in range(pow(base, exponent)):
+        pattern = num_to_pattern(i, base, exponent)
+        right_value = calculate_equation(right_side, pattern, operators)
+        if right_value == left_value:
+            return True
+    return False
+
+
+def get_total_calibration_result(lines: list, operators: list) -> int:
+    sum_values = 0
+    count = 0
+    for line in lines:
+        count += 1
+        value, right_side = parse_line(line)
+        if check_validity(value, right_side, operators):
+            sum_values += int(value)
+    return sum_values
+
+
 def main():
-    lines = get_lines("sample-input.txt")
-    # lines = get_lines("input.txt")
+    # lines = get_lines("sample-input.txt")
+    lines = get_lines("input.txt")
+    total_part1 = get_total_calibration_result(lines, ["+", "*"])
+    total_part2 = get_total_calibration_result(lines, ["+", "*", "|"])
+    print("Part 1: The total calibration result is:", total_part1)
+    print("Part 2: The total calibration result is:", total_part2)
 
 
 if __name__ == '__main__':