Forgot to save step 1

2022/20/example.txt

@@ -0,0 +1,7 @@
+1
+2
+-3
+3
+-2
+0
+4

2022/20/index.js

@@ -0,0 +1,109 @@
+const fs = require('fs/promises');
+
+const sum = (arr) => arr.reduce((total, num) => total+num, 0);
+const arrayOfLength = n => Array.from(Array(n).keys()).map(() => {});
+const modulo = (n, m) => ((n % m + m) % m);
+
+const keypress = async () => {
+  process.stdin.setRawMode(true)
+  return new Promise(resolve => process.stdin.once('data', data => {
+    const byteArray = [...data]
+    if (byteArray.length > 0 && byteArray[0] === 3) {
+      console.log('^C')
+      process.exit(1)
+    }
+    process.stdin.setRawMode(false)
+    resolve()
+  }))
+}
+
+const coords = ([x, y, z]) => `${x},${y},${z}`;
+
+const createNode = (arr, order, first, par, i = 0) => {
+  const node = {
+    val: arr[i],
+    par
+  }
+  order.push(node);
+  if(i < arr.length - 1) {
+    node.next = createNode(arr, order, first || node, node, i+1)
+    return node;
+  }
+  first.par = node;
+  node.next = first;
+  node.last = true;
+  return node;
+};
+
+const print = (node, first) => node === first ? [] : [node.val, ...print(node.next, first || node)];
+
+const key = 811589153;
+
+const main = async () => {
+  const input = (await fs.readFile("./input.txt", 'utf8')).slice(0, -1).split("\n").map(x => parseInt(x) * key);
+
+  const order = [];
+  let head = createNode(input, order, 0);
+
+  const shiftIntoOffset = (node, offset) => {
+    if(offset === 0) {
+      return;
+    }
+
+    let replace = node.next;
+    node.par.next = replace;
+    replace.par = node.par;
+    if(node === head) {
+      head = node.next;
+    }
+
+    for(let i = 0; i < offset; ++i) {
+      replace = replace.next;
+    }
+    if(replace === head) {
+      head = node;
+    }
+    replace.par.next = node;
+    node.par = replace.par;
+    node.next = replace;
+    replace.par = node;
+    return;
+  }
+
+  const mix = () => {
+    for(let i = 0; i < order.length; i++) {
+      const node = order[i];
+
+      const shiftBy = modulo(node.val, input.length - 1);
+
+      if(shiftBy !== 0) {
+        shiftIntoOffset(node, shiftBy);
+      }
+    }
+  };
+  for(let i = 0; i < 10; ++i) {
+    mix();
+  }
+
+  console.log("Mixed!");
+  const getAnswer = () => {
+    const answer = [];
+    let node = order.find(x => 0 === x.val);
+    let i = 0;
+    while(answer.length < 3) {
+      if(i === 1000 % input.length
+        || i === 2000 % input.length
+        || i === 3000 % input.length
+      ) {
+          answer.push(node.val);
+      }
+      node = node.next;
+      ++i;
+    }
+    return answer;
+  };
+  console.log("Answer: ", sum(getAnswer()));
+}
+
+
+main();