华为2016研发工程师编程题:字符集合

import java.util.Scanner;
public class Main{
    public static void main(String[] args){
        Scanner in = new Scanner(System.in);
        while(in.hasNext()){
            String  str = in.next();
            char[] chars = str.toCharArray();
            for(int i = 0;i<chars.length;i++){
                for(int j =i+1;j< chars.length;j++){
                    if(chars[i]!=‘+‘ && chars[i] == chars[j]){
                        chars[j] = ‘+‘;
                    }
                }
            }
            String res ="";
            for(int i =0;i<chars.length ;i++){
                if(chars[i] != ‘+‘){
                    res += chars[i]+"";
                }
            }
            String res2 = String.valueOf(chars);
            //System.out.println(res);
            System.out.println( res2.replaceAll("[+]","") );
             
        }
    }
}

import java.util.Scanner;public class Main{
    public static void main(String[] args){
        Scanner in = new Scanner(System.in);
        while(in.hasNext()){
            String  str = in.next();
            int[] A = new int[256];
            for(int i = 0;i< str.length() ;i++){
                char ch = str.charAt(i);
                A[ch]++;
            }
            String res="";
            for(int i = 0;i< str.length();i++){
                char ch = str.charAt(i);
                if(A[ch]!=0){
                    res+=ch;
                    A[ch] = 0;
                }
            }
            System.out.println(res);
            
        }
    }
}