linked_lists_unfinished

function arrayToList(arr) {
  for (var i=arr.length-1; i >= 0; i--) {
    var list = {value: arr[i], rest: (list || null)};
  }
  return list;
};

function listToArray(list) {
  var arr = [];
  for (var node=list; node; node=node.rest)
    arr.push(node.value);
  return arr;
};

function prepend(value, rest) {
  var list = {value: null, rest: null};
  list.value = value;
  list.rest = rest;
  return list;
};
function nth(list, n) {
  // WHAT IN THE ACTUAL FUCK!!!
};
console.log(arrayToList([10, 20]));
// → {value: 10, rest: {value: 20, rest: null}}
console.log(listToArray(arrayToList([10, 20, 30])));
// → [10, 20, 30]
console.log(prepend(10, prepend(20, null)));
// → {value: 10, rest: {value: 20, rest: null}}
console.log(nth(arrayToList([10, 20, 30]), 1));
// → 20