Invers.java

package test;

public class Invers {

	public static void main(String[] args) {
	
           String str="abcd efgh iklmnop";
           String str1=null;
           String str2="a";
           String str3="   ";
           String str4="aba";
           
           System.out.println(inverse(str));
           System.out.println(inverse(str1));
           System.out.println(inverse(str2));
           System.out.println(inverse(str3));
           System.out.println(inverse(str4));
	}
	static String inverse(String str)
	{
		if(str==null || str.length()<1)
			return "Give me another string";
		
		if(str.length()==1)
			return"Only one symvol, inversion have no sense";
		
		 char[]ar=str.toCharArray();
         char temp;
         boolean flag=false;
         
         for(int i=0,j=ar.length-1; i<=j ; i++,j--)
         {
        	 if(ar[i]!=ar[j])
        	 {
        	   temp=ar[i];
        	   ar[i]=ar[j];
        	   ar[j]=temp;
        	   flag=true;
        	 }
         }
         
        if(flag)
		  return new String(ar);
        
        return "Polindrom, inversion have no sense";
	}

}