all done

day25/part1.js

@@ -0,0 +1,36 @@
+var state = "A";
+var tape = {};
+var pointer = 0;
+var actions = {
+	A: [
+		[1, 1, "B"], [0, -1, "B"]
+	],
+	B: [
+		[0, 1, "C"], [1, -1, "B"]
+	],
+	C: [
+		[1, 1, "D"], [0, -1, "A"]
+	],
+	D: [
+		[1, -1, "E"], [1, -1, "F"]
+	],
+	E: [
+		[1, -1, "A"], [0, -1, "D"]
+	],
+	F: [
+		[1, 1, "A"], [1, -1, "E"]
+	],
+}
+aactions = {
+	A: [[1,1,"B"],[0,-1,"B"]],
+	B: [[1,-1,"A"],[1,1,"A"]],
+}
+for(var i = 0; i < 12629077; i++){
+	var action = actions[state][tape[pointer] ? 1 : 0];
+	//console.log(state, pointer, tape);
+	tape[pointer] = action[0];
+	pointer += action[1];
+	state = action[2];
+}
+console.log(tape);
+console.log(Object.keys(tape).map(a=>(tape[a])).reduce((a,b)=>(a+b)));