Add day 8

2020-12-11 23:26:40 -06:00
parent 3619d3baec
commit 67d6b76449
5 changed files with 787 additions and 0 deletions
@@ -0,0 +1,78 @@
+class Comp {
+  static final Comp _singleton = Comp._internal();
+  int _pc;
+  int _acc;
+  Set<int> _loopTest;
+  int _swapJmp = -1;
+  int _swapNop = -1;
+
+  factory Comp() {
+    return _singleton;
+  }
+
+  // singleton's constructor
+  Comp._internal() {
+    reset();
+  }
+
+  void reset() {
+    _pc = 0;
+    _acc = 0;
+    _loopTest = {};
+  }
+
+  void swapJmp(int index) {
+    _swapJmp = index;
+    _swapNop = -1;
+  }
+
+  void swapNop(int index) {
+    _swapNop = index;
+    _swapJmp = -1;
+  }
+
+  int get pc => _pc;
+  int get acc => _acc;
+
+  bool execute(String command) {
+    var _newPC = _pc;
+    var _newAcc = _acc;
+
+    // print(command);
+    var parse = command.split(' ');
+    var _val = int.parse(parse[1]);
+    var instruction = parse[0];
+    if (_swapJmp >= 0 && _swapJmp == _pc) {
+      instruction = 'nop';
+    } 
+    if (_swapNop >= 0 && _swapNop == _pc) {
+      instruction = 'jmp';
+    } 
+    // print('$instruction:$_val  pc=$_pc  swpJmp=$_swapJmp  swpNop=$_swapNop');
+    switch (instruction) {
+      case 'nop':
+        _newPC++;
+        break;
+      case 'acc':
+        _newAcc += _val;
+        _newPC++;
+        break;
+      case 'jmp':
+        _newPC += _val;
+        break;
+      default:
+      print('********** ERROR **********');
+        break;
+    }
+    if (_loopTest.contains(_newPC)) {
+      return false;
+    }
+    _pc = _newPC;
+    _acc = _newAcc;
+    _loopTest.add(_pc);
+    return true;
+  }
+
+  @override
+  String toString() => 'pc:$_pc -- acc:$_acc';
+}