/**
 * @param {number[]} nums
 * @return {number[]}
 */
const findDisappearedNumbers = function (nums) {
  const numsslen = nums.length, res = [];
  for (let i = 0; i < numsslen; ++i) {
    const val = Math.abs(nums[i]) - 1;
    if (nums[val] > 0) {
      nums[val] = -nums[val];
    }
  }
  for (let i = 0; i < numsslen; ++i) {
    if (nums[i] > 0) {
      res.push(i + 1);
    }
  }
  return res;
};