Leetcode 26. Remove Duplicates from Sorted Array

 public class Solution {  
   public int RemoveDuplicates(int[] nums) {  
     if (nums == null || nums.Length == 0)  
     {  
       return 0;  
     }  
     int fast = 1;  
     int slow = 0;  
     while (fast < nums.Length)  
     {  
       if (nums[fast] == nums[slow])  
       {  
         fast++;  
         continue;  
       }  
       slow++;  
       nums[slow] = nums[fast];  
       fast++;  
     }  
     return slow+1;  
   }  
 }