day8.py

#!/usr/bin/env python3

import os
import sys
import random

src = open("input.txt", "r").readlines()

src2 = """nop +0
acc +1
jmp +4
acc +3
jmp -3
acc -99
acc +1
jmp -4
acc +6""".splitlines()

src = [r.strip() for r in src]

def run(patch_addr):
    acc = 0
    eip = 0

    prog = []

    for line in src:
        t = line.split(" ")
        prog.append([t[0], int(t[1])])

    patch_inst = prog[patch_addr][0]

    if patch_inst == "jmp":
        prog[patch_addr][0] = "nop"

    if patch_inst == "nop":
        prog[patch_addr][0] = "jmp"

    visited = set()

    while True:
        if eip >= len(prog):
            print("overflow!")
            break

        inst = prog[eip][0]
        p1 = prog[eip][1]

        # print(f"eip={eip} acc={acc} inst={inst} p1={p1}")

        if eip in visited:
            print("loop")
            break

        visited.add(eip)

        if inst == "nop":
            eip += 1
            continue

        if inst == "acc":
            acc += p1
            eip += 1
            continue

        if inst == "jmp":
            eip += p1
            continue

    return acc

for x in range(len(src)):
    print(x, run(x))