/**
 * Return an array of size *returnSize.
 * Note: The returned array must be malloced, assume caller calls free().
 */
int* findDisappearedNumbers(int* nums, int numsSize, int* returnSize) {

  int *arr;
  int temp1, temp2;
  int i=0, j=0;

  for(i=0;i<numsSize;i++) {
    if(nums[i] != 0) {
      temp1 = nums[nums[i]-1];
      nums[nums[i]-1] = 0;
      while(temp1 != 0) {
        temp2 = nums[temp1-1];
        nums[temp1-1] = 0;
        temp1 = temp2;
      }
    }
  }

  for(i=0;i<numsSize;i++) {
    if(nums[i] != 0)
      *returnSize = *returnSize + 1;
  }
  arr = (int *) malloc((*returnSize)*sizeof(int));
  for(i=0;i<numsSize && j < *returnSize;i++) {
    if(nums[i] != 0)X
      arr[j++] = i+1;
  }
  return arr;

}