aoc/2020/08/08.py
2020-12-10 17:11:17 -06:00

69 lines
1.5 KiB
Python

def read_file():
with open("input.txt","r") as f:
return f.read().split('\n')
def process(instructions):
acc = 0
i = 0
visited = []
while True:
if i not in range(len(instructions)):
# we've terminated bois
return acc, False
if i in visited:
# it loops
return acc, True
visited.append(i)
instruction = instructions[i]
operation = instruction[:3]
argument = instruction[4:]
if operation == "nop":
i += 1
elif operation == "acc":
acc += int(argument)
i += 1
elif operation == "jmp":
i += int(argument)
def part1(instructions):
acc, repeats = process(instructions)
return acc
def terminates(instructions):
if process(instructions):
return False
return True
def part2(instructions):
acc = 0
i = 0
visited = []
while True:
if i in visited:
for i in reversed(visited):
new_instructions = [instruction for instruction in instructions]
if instructions[i][:3] == "jmp":
new_instructions[i] = instructions[i].replace("jmp","nop")
elif instructions[i][:3] == "nop":
new_instructions[i] = instructions[i].replace("nop","jmp")
new_acc, repeats = process(new_instructions)
if not repeats:
return new_acc
visited.append(i)
instruction = instructions[i]
operation = instruction[:3]
argument = instruction[4:]
if operation == "nop":
i += 1
elif operation == "acc":
acc += int(argument)
i += 1
elif operation == "jmp":
i += int(argument)
def main():
instructions = read_file()
print(part1(instructions), part2(instructions))
if __name__ == "__main__":
main()