makeAStringPalindrome.java

public class makeStringPalindrome {
    public static int add(String str){
        int start=0, end= str.length()-1;
        int len=end,insertAt=0;
        int count=0;
        StringBuilder strNew= new StringBuilder(str);
        while(start<end){
            if(str.charAt(start)==str.charAt(end)){
                start++;
                end--;
            }
            else{
                if(count==0){
                    if(end<str.length()-1){
                        for(int i=end+1; i<str.length(); i++){
                            strNew.insert(0,str.charAt(i));
                            insertAt++;
                        }
                    }
                    else {
                        strNew.insert(0, str.charAt(end));
                        insertAt++;
                    }
                }
                else{
                    strNew.insert(insertAt++,str.charAt(end));
                }
                count++;
                start=0;
                end= --len;
            }
        }
        System.out.println("New palindromic string: "+ strNew);
        return count;
    }

    public static void main(String[] args) {
        Scanner sc= new Scanner(System.in);
        String str= sc.next();
        System.out.println("Min num of characters add in front of String: "+ add(str));
    }
}