var canReach = function (arr, start) {
  const stack = [start];
  const visited = [];

  const isVisited = (i) => visited[i];
  const isBounded = (i) => i >= 0 && i < arr.length;
  const isValueZero = (i) => arr[i] === 0;

  while (stack.length) {
    const current = stack.pop();
    visited[current] = true;

    if (isValueZero(current)) return true;

    for (let i = -1; i < 2; i += 2) {
      const next = current + arr[current] * i;

      !isVisited(next) && isBounded(next) && stack.push(next);
    }
  }
  return false;
};