137. Single Number II

Given an array of integers, every element appears three times except for one. Find that single one.

代码如下：

 public class Solution {
     public int singleNumber(int[] nums) {
         if(nums.length==1||nums.length==2)
         return nums[0];
         Arrays.sort(nums);
         for(int i=0;i<nums.length-2;)
         {
             if(nums[i]==nums[i+1]&&nums[i]==nums[i+2])
             i=i+3;
             else return nums[i];
         }
         return nums[nums.length-1];
     }
 }