public class Solution {
public List<Integer> findDisappearedNumbers(int[] nums) {
List<Integer> rst = new ArrayList<Integer>();
if (nums == null || nums.length == 0) return rst;
for (int i = 0; i < nums.length; i++) {
int index = Math.abs(nums[i]) - 1;
if (nums[index] > 0) {
nums[index] = -nums[index];
}
}
for (int i = 0; i < nums.length; i++) {
if (nums[i] > 0) {
rst.add(i + 1);
}
}
return rst;
}
}