题目：

题解：

class Solution {public List<Integer> findDisappearedNumbers(int[] nums) {int n = nums.length;for (int num : nums) {int x = (num - 1) % n;nums[x] += n;}List<Integer> ret = new ArrayList<Integer>();for (int i = 0; i < n; i++) {if (nums[i] <= n) {ret.add(i + 1);}}return ret;}
}