# Sum of 2 numbers in an array

**Problem statement**

Identify whether there exists a pair of numbers in an array such that their sum is equal to .

**Input**

The first line contains one integer , which is the sum we are trying to find. The second line contains one integer , which is the length of the array. This is followed by lines each containing one element of the array.

**Output**

Output if there exists a pair of numbers in the array such that their sum equals . If such a pair does not exist, output .

**Sample Input**

66 10 18 11 21 28 31 38 40 55 60 62

**Sample Output**

1

**Solution**

public class SumOfTwoNumbers { public static void main(String[] args) throws FileNotFoundException { System.setIn(new FileInputStream(System.getProperty("user.home") + "/" + "in.txt")); Scanner in = new Scanner(System.in); int n = in.nextInt(); int m = in.nextInt(); int[] a = new int[m]; for (int i=0; inum2index = new HashMap (); for (int i=0; i