days 11-16

day11/part1.js

@@ -0,0 +1,30 @@
+var input = require("fs").readFileSync("input.txt").toString().replace("\n", "");
+var dirs = input.split(",");
+
+var replacements = [
+	[["n", "s"], ""],
+	[["ne", "sw"], ""],
+	[["nw", "se"], ""],
+	[["ne", "nw"], "n"],
+	[["se", "sw"], "s"],
+	[["ne", "s"], "se"],
+	[["se", "n"], "ne"],
+	[["sw", "n"], "nw"],
+	[["nw", "s"], "sw"],
+];
+
+var oldlength = 0;
+while(dirs.length != oldlength){
+	oldlength = dirs.length;
+	for(var replacement of replacements){
+		if(dirs.indexOf(replacement[0][0]) > -1 && dirs.indexOf(replacement[0][1]) > -1){
+			dirs.splice(dirs.indexOf(replacement[0][0]), 1);
+			dirs.splice(dirs.indexOf(replacement[0][1]), 1);
+			if(replacement[1]){
+				dirs.push(replacement[1]);
+			}
+		}
+	}
+}
+
+console.log(dirs.length);

day11/part2.js

@@ -0,0 +1,41 @@
+var input = require("fs").readFileSync("input.txt").toString().replace("\n", "");
+var dirs = input.split(",");
+function simplify(dirs){
+	var replacements = [
+		[["n", "s"], ""],
+		[["ne", "sw"], ""],
+		[["nw", "se"], ""],
+		[["ne", "nw"], "n"],
+		[["se", "sw"], "s"],
+		[["ne", "s"], "se"],
+		[["se", "n"], "ne"],
+		[["sw", "n"], "nw"],
+		[["nw", "s"], "sw"],
+	];
+	var oldlength = 0;
+	while(dirs.length != oldlength){
+		oldlength = dirs.length;
+		for(var replacement of replacements){
+			if(dirs.indexOf(replacement[0][0]) > -1 && dirs.indexOf(replacement[0][1]) > -1){
+				dirs.splice(dirs.indexOf(replacement[0][0]), 1);
+				dirs.splice(dirs.indexOf(replacement[0][1]), 1);
+				if(replacement[1]){
+					dirs.push(replacement[1]);
+				}
+			}
+		}
+	}
+	return dirs;
+}
+
+var maxlen = 0;
+
+for(var i = 0; i < dirs.length; i++){
+	var sub = dirs.slice(0, i);
+	var len = simplify(sub).length;
+	if(len > maxlen){
+		maxlen = len;
+	}
+	console.log(i/dirs.length);
+}
+console.log(maxlen);

day12/part1.js

@@ -0,0 +1,11 @@
+var input = require("fs").readFileSync("input.txt").toString();
+var links = input.split("\n").filter((a)=>(a)).map((a)=>(a.split(" <-> ")[1].split(", ").map((b)=>(parseInt(b)))));
+var attached = [];
+function add(x){
+	if(attached.indexOf(x) == -1){
+		attached.push(x);
+		links[x].forEach((a)=>(add(a)));
+	}
+}
+add(0);
+console.log(attached.length);

day12/part2.js

@@ -0,0 +1,19 @@
+var input = require("fs").readFileSync("input.txt").toString();
+var links = input.split("\n").filter((a)=>(a)).map((a)=>(a.split(" <-> ")[1].split(", ").map((b)=>(parseInt(b)))));
+var allvisited = [];
+function getconnected(x, items){
+	if(items.indexOf(x) == -1){
+		items.push(x);
+		links[x].forEach((a)=>(getconnected(a, items)));
+	}
+	return items;
+}
+var i = 0;
+while(allvisited.length != Object.keys(links).length){
+	var start = Object.keys(links).map((a)=>(parseInt(a))).filter((a)=>(allvisited.indexOf(a) == -1))[0];
+	console.log(i, start);
+	var newgroup = getconnected(start, []);
+	allvisited = allvisited.concat(newgroup);
+	i++
+}
+console.log(i);

day13/input.txt

@@ -0,0 +1,43 @@
+0: 4
+1: 2
+2: 3
+4: 5
+6: 6
+8: 4
+10: 8
+12: 6
+14: 6
+16: 8
+18: 8
+20: 6
+22: 8
+24: 9
+26: 8
+28: 8
+30: 12
+32: 12
+34: 10
+36: 12
+38: 12
+40: 10
+42: 12
+44: 12
+46: 12
+48: 12
+50: 12
+52: 14
+54: 14
+56: 12
+58: 14
+60: 14
+62: 14
+64: 17
+66: 14
+70: 14
+72: 14
+74: 14
+76: 14
+78: 18
+82: 14
+88: 18
+90: 14

day13/part1.js

@@ -0,0 +1,4 @@
+var input = require("fs").readFileSync("input.txt").toString();
+var depths = input.split("\n").filter((a)=>(a)).map((a)=>(a.split(": ").map((b)=>(parseInt(b))))).reduce((dep, a)=>{dep[a[0]] = a[1]; return dep;}, []);
+var severity = depths.map((a, i)=>(a*i)).filter((a, i)=>((i % (a/i*2 - 2)) == 0)).reduce((a, b)=>(a+b));
+console.log(severity);

day13/part2.js

@@ -0,0 +1,8 @@
+var input = require("fs").readFileSync("input.txt").toString();
+var depths = input.split("\n").filter((a)=>(a)).map((a)=>(a.split(": ").map((b)=>(parseInt(b))))).reduce((dep, a)=>{dep[a[0]] = a[1]; return dep;}, []);
+var caught = (del)=>(depths.filter((a, i)=>(((i+del) % (a*2 - 2)) == 0)).length > 0);
+for(var i = 0; i < 10000000; i++){
+	if(caught(i) == false){
+		console.log(i);
+	}
+}

day14/part1.js

@@ -0,0 +1,32 @@
+function hash(input){
+	var list = [];
+	for(var i = 0; i < 256; i++){
+		list.push(i);
+	}
+	var pos = 0;
+	var lengths = input.split("").filter((a)=>(a)).map((a)=>(a.charCodeAt(0))).concat([17, 31, 73, 47, 23]);
+	var skip = 0;
+	for(var x = 0; x < 64; x++){
+		for(var length of lengths){
+			for(var i = 0; i < (length/2); i++){
+				var a = list[(pos+i)%list.length];
+				var b = list[(pos+length-1-i)%list.length];
+				list[(pos+i)%list.length] = b;
+				list[(pos+length-1-i)%list.length] = a;
+			}
+			pos += length + skip;
+			pos = pos % list.length;
+			skip += 1;
+		}
+	}
+
+	var hash = list.reduce((arr, a, i)=>{arr[Math.floor(i/16)] = arr[Math.floor(i/16)] ^ a; return arr;}, []);
+	return hash.map((a)=>(a.toString(2).split("").map((b)=>(parseInt(b))).reduce((a,b)=>(a+b)))).reduce((a, b)=>(a+b));
+}
+
+var total = 0;
+for(var i = 0; i < 128; i++){
+	total += hash("xlqgujun-" + i);
+}
+
+console.log(total);

day14/part2.js

@@ -0,0 +1,61 @@
+function hash(input){
+	var list = [];
+	for(var i = 0; i < 256; i++){
+		list.push(i);
+	}
+	var pos = 0;
+	var lengths = input.split("").filter((a)=>(a)).map((a)=>(a.charCodeAt(0))).concat([17, 31, 73, 47, 23]);
+	var skip = 0;
+	for(var x = 0; x < 64; x++){
+		for(var length of lengths){
+			for(var i = 0; i < (length/2); i++){
+				var a = list[(pos+i)%list.length];
+				var b = list[(pos+length-1-i)%list.length];
+				list[(pos+i)%list.length] = b;
+				list[(pos+length-1-i)%list.length] = a;
+			}
+			pos += length + skip;
+			pos = pos % list.length;
+			skip += 1;
+		}
+	}
+
+	var hash = list.reduce((arr, a, i)=>{arr[Math.floor(i/16)] = arr[Math.floor(i/16)] ^ a; return arr;}, []);
+	return hash.map((a)=>(("00000000" + a.toString(2)).slice(-8).split("").map((b)=>(parseInt(b))))).reduce((a, b)=>(a.concat(b)));
+}
+
+var grid = [];
+for(var i = 0; i < 128; i++){
+	grid.push(hash("xlqgujun-" + i));
+}
+
+var seen = [];
+function calc(x, y){
+	return (x + (128 * y));
+}
+function scanNeighbours(x, y){
+	if(grid[x]){
+		if(grid[x][y]){
+			if(seen.indexOf(calc(x,y)) == -1){
+				seen.push(calc(x,y));
+				scanNeighbours(x+1,y);
+				scanNeighbours(x-1,y);
+				scanNeighbours(x,y+1);
+				scanNeighbours(x,y-1);
+			}
+		}
+	}
+}
+
+var total = 0;
+for(var x = 0; x < 128; x++){
+	for(var y = 0; y < 128; y++){
+		if(grid[x][y]){
+			if(seen.indexOf(calc(x,y)) == -1){
+				total++;
+				scanNeighbours(x,y);
+			}
+		}
+	}
+}
+console.log(total);

day15/part1.js

@@ -0,0 +1,13 @@
+var a = 591;
+var b = 393;
+var total = 0;
+for(var i = 0; i <= 40000000; i++){
+	a = (a*16807)%2147483647;
+	b = (b*48271)%2147483647;
+	if(a.toString(2).slice(-16) == b.toString(2).slice(-16)){
+		total++;
+		console.log(i);
+		console.log(a, b);
+	}
+}
+console.log(total);

day15/part2.js

@@ -0,0 +1,19 @@
+var a = 591;
+var b = 393;
+var total = 0;
+for(var i = 0; i <= 5000000; i++){
+	do{
+		a = (a*16807)%2147483647;
+	}
+	while(a%4 != 0)
+	do{
+		b = (b*48271)%2147483647;
+	}
+	while(b%8 != 0)
+	if(a.toString(2).slice(-16) == b.toString(2).slice(-16)){
+		total++;
+		console.log(i);
+		console.log(a, b);
+	}
+}
+console.log(total);

day16/part1.js

@@ -0,0 +1,11 @@
+var items = "abcdefghijklmnop".split("");
+s = (i) => {items = items.splice(-i).concat(items);}
+x = (a,b) => {[items[a], items[b]] = [items[b], items[a]]}
+p = (a,b) => {x(items.indexOf(a), items.indexOf(b))}
+
+var input = require("fs").readFileSync("input.txt").toString().replace("\n", "");
+var input = "," + input + ",";
+var expr = input.replace(/,/g, ");").replace(/;([sxp])/g, ";$1(").replace(/([a-z])\/([a-z])/g, "'$1'/'$2'").replace(/\//g, ",");
+expr = expr.substring(2);
+eval(expr);
+console.log(items.join(""));

day16/part2.js

@@ -0,0 +1,19 @@
+var items = "abcdefghijklmnop".split("");
+s = (i) => {items = items.splice(-i).concat(items);}
+x = (a,b) => {[items[a], items[b]] = [items[b], items[a]]}
+p = (a,b) => {x(items.indexOf(a), items.indexOf(b))}
+
+var input = require("fs").readFileSync("input.txt").toString().replace("\n", "");
+var input = "," + input + ",";
+var expr = input.replace(/,/g, ");").replace(/;([sxp])/g, ";$1(").replace(/([a-z])\/([a-z])/g, "'$1'/'$2'").replace(/\//g, ",");
+expr = expr.substring(2);
+var state = "";
+var states = [];
+while(states.indexOf(state) == -1){
+	states.push(state);
+	eval(expr);
+	state = items.join("");
+}
+states = states.filter((a)=>(a));
+var num = 1000000000;
+console.log(states[(num-1)%states.length]);