Add day 4 solution

03/example

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+vJrwpWtwJgWrhcsFMMfFFhFp
+jqHRNqRjqzjGDLGLrsFMfFZSrLrFZsSL
+PmmdzqPrVvPwwTWBwg
+wMqvLMZHhHMvwLHjbvcjnnSBnvTQFn
+ttgJtRGJQctTZtZT
+CrZsJsPPZsGzwwsLwLmpwMDw

03/rucksacks.py

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+
+import fileinput
+
+from typing import Iterable
+
+def letter_to_priority(i: str) -> int:
+    i = ord(i)
+    return (i & 0b11111) + (~((i & 0b00100000) >> 5) & 1) * 26
+
+def compartment(items: str) -> int:
+    field = 0
+    for item in items:
+        field |= 1 << (letter_to_priority(item) - 1)
+    return field
+
+def bitmap_to_priority(field: int) -> int:
+    for idx in range(52):
+        if field & 0b1:
+            return idx + 1
+        else:
+            field >>= 1
+
+def solve(lines: Iterable[str]) -> int:
+    score = 0
+    for line in map(lambda x: x.strip(), lines):
+        items = len(line)
+        lh = compartment(line[:items//2])
+        rh = compartment(line[items//2:])
+        score += bitmap_to_priority(lh & rh)
+    return score
+
+def solveb(lines: Iterable[str]) -> int:
+    score = 0
+    iterator = map(lambda x: x.strip(), lines.__iter__())
+    for first in iterator:
+        second = next(iterator)
+        third = next(iterator)
+        score += bitmap_to_priority(compartment(first) & compartment(second) & compartment(third))
+    return score
+
+if __name__ == "__main__":
+    print(solve(fileinput.input()))
+    print(solveb(fileinput.input()))
+
+        
+    

04/cleanup.py

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+
+import fileinput
+from typing import Iterable
+
+class Range:
+
+    rmin: int
+    rmax: int
+    length: int
+
+    def __init__(self, rang: str):
+        self.rmin,self.rmax = map(lambda x: int(x), rang.strip().split('-'))
+        self.length = self.rmax - self.rmin + 1
+
+
+def solve(lines: Iterable[str]) -> int:
+    score = 0
+    for line in lines:
+        elf1, elf2 = map(lambda x: Range(x), line.strip().split(','))
+        if elf2.length > elf1.length:
+            elf2,elf1 = (elf1, elf2)
+        if elf1.rmin <= elf2.rmin and elf1.rmax >= elf2.rmax:
+            score += 1
+    return score
+
+def solveb(lines: Iterable[str]) -> int:
+    score = 0
+    for line in lines:
+        elf1, elf2 = map(lambda x: Range(x), line.strip().split(','))
+        if elf2.length > elf1.length:
+            elf2,elf1 = (elf1, elf2)
+        if elf1.rmin <= elf2.rmax and elf1.rmax >= elf2.rmin:
+            score += 1
+    return score
+
+
+if __name__ == "__main__":
+    print(solve(fileinput.input()))
+    print(solveb(fileinput.input()))

04/example

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+2-4,6-8
+2-3,4-5
+5-7,7-9
+2-8,3-7
+6-6,4-6
+2-6,4-8