Day 8

day08/part2.py

@@ -0,0 +1,30 @@
+lines = list(map(lambda y: (y[0], int(y[1])), (x.strip().split() for x in open("input.txt"))))
+length = len(lines)
+
+for change_idx in range(length):
+    old_value = lines[change_idx]
+    if lines[change_idx][0] == 'nop':
+        lines[change_idx] = ('jmp', lines[change_idx][1])
+    elif lines[change_idx][0] == 'jmp':
+        lines[change_idx] = ('nop', lines[change_idx][1])
+    executed = set()
+    pos = 0
+    acc = 0
+    while True:
+        cmd, val = lines[pos]
+        executed.add(pos)
+        if cmd == 'nop':
+            pos += 1
+        elif cmd == 'acc':
+            acc += val
+            pos += 1
+        elif cmd == 'jmp':
+            pos += val
+        if pos in executed:
+            break
+        if pos >= length:
+            print('invalid index:', pos)
+            print('changed index:', change_idx)
+            print('current value:', acc)
+            break
+    lines[change_idx] = old_value