数组中重复的数字

class Solution {
    public int findRepeatNumber(int[] nums) {
      int temp;
        for(int i=0;i<nums.length;i++){

  　　　　　　for (;nums[i]!=i;){

                if(nums[i]==nums[nums[i]]){

                    return nums[i];

                }

                temp=nums[i];

                nums[i]=nums[temp];

                nums[temp]=temp;

            }

        }
        return -1;




    }
}