TwoStrings.java

//https://www.hackerrank.com/challenges/two-strings

import java.io.*;

public class TwoStrings 
{
	public static void main(String[] args) throws IOException
	{
		StringBuffer sb = new StringBuffer();
		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
    
		//For each test case
		for(byte T = Byte.parseByte(br.readLine()); T > 0; --T)
		{
      
			//Get strings
			final char[] A = br.readLine().toCharArray();
			final char[] B = br.readLine().toCharArray();
      
			//Check if both strings share a common substring
			sb.append(hasSubstring(A, B) ? "YES\n" : "NO\n");
		}
		System.out.print(sb);
	}
  
	private static boolean hasSubstring(final char[] A, final char[] B)
	{    
		//Get presence of letters in string A
		int bitsA = 0;
		for(int i = 0, n = A.length; i < n; bitsA |= 1 << (A[i++] - 'a')){}
    
		//Get presence of letters in string B
		int bitsB = 0;
		for(int i = 0, n = B.length; i < n; bitsB |= 1 << (B[i++] - 'a')){}
    
		//Check if both strings have any letters in common
		return (bitsA & bitsB) != 0;
	}
}