add day 3

day3/day3.py

@@ -0,0 +1,89 @@
+import sys
+sys.path.append('../aoclib')
+
+from aoclib import Input
+import re
+
+def all_mul(s: list[str]) -> int:
+    total = 0
+    matches = re.findall(r'mul\((\d+),(\d+)\)', s)
+    for m in matches:
+        total += int(m[0]) * int(m[1])
+
+    return total
+    
+class Tokenizer(object):
+    regexp = re.compile(r"(do\(\)|don't\(\)|mul\((\d+),(\d+)\))")
+    def __init__(self, s: str):
+        self._string = s
+        self.count = 0
+
+    def __iter__(self):
+        return self
+
+    def __next__(self):
+        m = self.regexp.search(self._string)
+        if not m:
+            raise StopIteration
+
+        self.count += 1
+
+        self._string = self._string[m.end():]
+
+        a, b = 0, 0
+
+        if m.group(1).startswith('mul'):
+            a = int(m.group(2))
+            b = int(m.group(3))
+
+        t = Token(m.group(1), a, b)
+        return t
+
+
+class Token(object):
+    _do = "do()"
+    _dont = "don't()"
+    def __init__(self, s: str, a: int, b: int):
+        self._value = s
+        self.a = a
+        self.b = b
+
+    def do(self) -> bool:
+        return self._value == self._do
+
+    def dont(self) -> bool:
+        return self._value == self._dont
+
+    def mult(self) -> int:
+        return self.a * self.b
+
+    def __str__(self) -> str:
+        return f'{self._value}, {self.a}, {self.b}'
+     
+def solve2(s: str) -> int:
+    active = True
+    total = 0
+    tokens = Tokenizer(s)
+    for t in tokens:
+        if t.do():
+            active = True
+            continue
+        elif t.dont():
+            active = False
+            continue
+
+        if active:
+            total += t.mult()
+
+    return total
+
+
+if __name__ == '__main__':
+    #lines = Input('input_test2.txt').lines()
+    raw = Input('input.txt').raw()
+
+    #part 1
+    print('part 1:', all_mul(raw))
+
+    #part 2
+    print('part 2:', solve2(raw))