blob: 3763c785c6a2d44fcc99912b8d68b71bdc5afdbe (
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boot_code = list()
def gameon(acc, cx, sf):
"""emulates the game until a loop or the end"""
while cx not in sf:
sf.add(cx)
if cx == len(boot_code):
print(acc)
exit(0)
if boot_code[cx][0] == "acc":
acc += boot_code[cx][1]
elif boot_code[cx][0] == "jmp":
cx += boot_code[cx][1] - 1
else: # nop
pass
cx += 1
with open("input", "r") as file:
for line in file:
line = line.strip()
oparg = line.split(" ")
boot_code.append((oparg[0], int(oparg[1])))
cursor = 0
accumulator = 0
sofar = set()
# we are allowed to keep a 'main' branch and keep jmp/nops separate because
# task calls for only one instruction change over the whole code
while cursor not in sofar:
sofar.add(cursor)
if boot_code[cursor][0] == "acc":
accumulator += boot_code[cursor][1]
elif boot_code[cursor][0] == "jmp":
# one for the jmp
gameon(accumulator, cursor + boot_code[cursor][1], sofar.copy())
# one for the nop
gameon(accumulator, cursor + 1, sofar.copy())
cursor += boot_code[cursor][1] - 1
elif boot_code[cursor][0] == "nop":
# one for the nop
gameon(accumulator, cursor + 1, sofar.copy())
# one for the jmp
gameon(accumulator, cursor + boot_code[cursor][1], sofar.copy())
cursor += 1
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