Puzzle – Check if string is complete (contains all alphabets)

A string is said to be complete if it contains all the characters from a to z. Given a string, check if it complete or not. e.g.

Sample Input

3
wyyga
qwertyuioplkjhgfdsazxcvbnm
ejuxggfsts

Sample Output

NO
YES
NO

Solution using for loop and indexOf()

I wrote a quick function which is able to find this complete string.

package com.howtodoinjava.examples;
 
public class CheckAllAlphabetsAlgorithms
{
    public static void main(String[] args)
    {
        System.out.println( checkAllChars( "qwertyuioplkjhgfdsAzxcvbnm" ) );
        System.out.println( checkAllChars( "123" ) );
        System.out.println( checkAllChars( "ejuxggfsts" ) );
        System.out.println( checkAllChars( "wyyga" ) );
    }
     
    private static String checkAllChars ( String input )
    {
        //If input length is less than 26 then it can never be complete
        if(input.length() < 26)
        {
            return "FALSE";
        }
                 
        for (char ch = 'A'; ch <= 'Z'; ch++)
        {
            if (input.indexOf(ch) < 0 && input.indexOf((char) (ch + 32)) < 0)
            {
                return "FALSE";
            }
        }
        return "TRUE";
    }
}

Output:

TRUE
FALSE
FALSE
FALSE

Solution using for regular expressions

Here is a (ugly because I don’t like long regex) solution to find complete string using regex.

package com.howtodoinjava.examples;
 
public class CheckAllAlphabetsAlgorithms
{
    public static void main(String[] args)
    {
        System.out.println( checkAllCharsUsingRegex( "qwertyuioplkjhgfdsAzxcvbnm" ) );
        System.out.println( checkAllCharsUsingRegex( "123" ) );
        System.out.println( checkAllCharsUsingRegex( "ejuxggfsts" ) );
        System.out.println( checkAllCharsUsingRegex( "wyyga" ) );
    }
     
    private static String checkAllCharsUsingRegex ( String input )
    {
        //If input length is less than 26 then it can never be complete
        if(input.length() < 26)
        {
            return "FALSE";
        }
         
        String regex = "(?i)(?=.*a)(?=.*b)(?=.*c)(?=.*d)(?=.*e)(?=.*f)"
                + "(?=.*g)(?=.*h)(?=.*i)(?=.*j)(?=.*k)(?=.*l)(?=.*m)(?=.*n)"
                + "(?=.*o)(?=.*p)(?=.*q)(?=.*r)(?=.*s)(?=.*t)(?=.*u)(?=.*v)"
                + "(?=.*w)(?=.*x)(?=.*y)(?=.*z).*";
                 
        if(input.matches(regex)){
            return "TRUE";
        }
        return "FALSE";
    }
}

Output:

TRUE
FALSE
FALSE
FALSE

Happy Learning !!