Missing number in array - Given an array C of size N-1 and given that there are numbers from 1 to N with one element missing, the missing number is to be found.

MissingNumber.java

import java.util.Scanner;

public class MissingNumber {

	public static void main(String[] args) {
		// TODO Auto-generated method stub
		Scanner input = new Scanner(System.in);
		System.out.println("Please enter the value of N");
		int N = Integer.parseInt(input.nextLine());
		int expectedSum = (N * (N+1))/2;
		System.out.println("Enter Input Array");
		String [] numArray = input.nextLine().split(" ");
		int sum = 0;
		for (int i = 0; i < numArray.length; i++) {
			int number = Integer.parseInt(numArray[i]);
			sum = sum + number;
		}
		System.out.println(" Missing Number is " + (expectedSum-sum) );
		input.close();

	}

}