Find the Missing Number in Array 3
Get an array of Integers arr[]
with size n and find the first
missing number in the array arr[]. Assume
the array starts with smallest number and ends with greatest number. So find
the missing number between smallest to greatest. Return 0 if no missing number
found. Array may contains duplicates numbers. 
Example
Input 1:
5 
12 10 9 7 11 
Output 1:
8
Input 1:
6 
4 5 7 8 6 9
Output 1:
0
Try your Solution
Strongly recommended to Solve it on your own, Don't directly go to the solution given below.
Program or Solution
			
				
				
					import java.util.*;
class Missing_Number2
{
	public static void main(String args[])
    	{
		//Variable and  Object Declarations
       		Scanner input = new Scanner(System.in);
		int n,bool=0;
		
		//Getting size of Array & Declare Array arr[]
		n = input.nextInt();
		int arr[] = new int[n];
		//Get n values to array arr[]
		for(int i = 0; i<n; i++)
		{
			arr[i] = input.nextInt();
		}
		
		Arrays.sort(arr);
		for(int i = 1; i<n; i++)
		{
			
			if(arr[i]!=arr[i-1]+1 && arr[i]!=arr[i-1])
			{
				System.out.print(arr[i-1]+1);	
				bool = 1;
				break;
			}
			
		}
		if(bool==0)
		{
			System.out.print(0);
		}
	
		
		
      	}
}
								
				
			
		
		
					
		
		
								
		
