Class A

Hackerank/Java/Strong-password.java:23–164

// The code goes as follows:--

public class A {

// A class with name as [A] with a empty string INPUT -

    InputStream is;
    PrintWriter out;
    String INPUT = "";

   // The solution function to check the validity of the entered password is correct or not.
    
    void solve()
    {
        String numbers = "0123456789",
                lower_case = "abcdefghijklmnopqrstuvwxyz",
                upper_case = "ABCDEFGHIJKLMNOPQRSTUVWXYZ",
                special_characters = "!@#$%^&*()-+";
        int n = ni();
        char[] s = ns(n);
        int need = 0;
        int x = 0;
        for(char c : s){
            if(numbers.indexOf(c) >= 0)x |= 1;
            if(lower_case.indexOf(c) >= 0)x |= 2;
            if(upper_case.indexOf(c) >= 0)x |= 4;
            if(special_characters.indexOf(c) >= 0)x |= 8;
        }
        need = 4-Integer.bitCount(x);
        out.println(Math.max(6-n, need));
    }
    
    void run() throws Exception
    {
        is = INPUT.isEmpty() ? System.in : new ByteArrayInputStream(INPUT.getBytes());
        out = new PrintWriter(System.out);
        
        long s = System.currentTimeMillis();
        solve();
        out.flush();
        if(!INPUT.isEmpty())tr(System.currentTimeMillis()-s+"ms");
    }
    
    public static void main(String[] args) throws Exception { new A().run(); }
    
    private byte[] inbuf = new byte[1024];
    public int lenbuf = 0, ptrbuf = 0;
    
    private int readByte()
    {
        if(lenbuf == -1)throw new InputMismatchException();
        if(ptrbuf >= lenbuf){
            ptrbuf = 0;
            try { lenbuf = is.read(inbuf); } catch (IOException e) { throw new InputMismatchException(); }
            if(lenbuf <= 0)return -1;
        }
        return inbuf[ptrbuf++];
    }
    
    private boolean isSpaceChar(int c) { return !(c >= 33 && c <= 126); }