Return Permutations - String

public class solution {
	
	public static String[] permutationOfString(String input){
		// Write your code here
        if(input.length()==0){
            String y[]={" "};
            return y;
        }
        String smallAns[]= permutationOfString(input.substring(1));
		String array[]=new String[input.length()*smallAns.length];
        int k=0;
        for(int i=0;i<smallAns.length;i++){
            for(int j=0;j<smallAns[i].length();j++){
                array[k++]=smallAns[i].substring(0,j)+input.charAt(0)+smallAns[i].substring(j);            }
        }
        return array;
	}
	
}