DiffK - facebook code lab - pass all test cases - keep changing the code - line 24 - line 27

DiffK2.java

public class Solution {
	public int diffPossible(List<Integer> a, int b) {
	    if(a == null || a.size() == 0 || a.size() ==1) 
	        return 0; 
	  
	    int len = a.size(); 
	    
	    List<Integer> arrB = new ArrayList<Integer>(); 
	    
	    for(int i=0; i< len;i++)
	    {
	        int val = a.get(i).intValue(); 
	        arrB.add(i, Integer.valueOf( val + b)); 
	    }
	  
	    int start1 = 0; 
	    int start2 = 0; 
	    while(start1 < len && start2 < len )
	    {
	        int top  = a.get(start1).intValue(); 
	        int down = arrB.get(start2).intValue(); 
	        if(top == down )
	        {
	            if(start1 == start2) // bug001: [1, 2,3], 0, return 0, not 1
	            {
	                start1++; // bug002: [1, 2,2,3 ], 0, return 1, not retun 0. 
	            }
	            else
	                return 1; 
	        }
	        else if(top < down)
	            start1++; 
	        else if(top > down)
	            start2++; 
	    }
	    
	    return 0; 
	}
	

	
	
}