题解 | 字符串合并处理

import java.util.*;

// 注意类名必须为 Main, 不要有任何 package xxx 信息
public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        String str=sc.nextLine();
        String []st=str.split(" ");
        System.out.println(adjust(combine2(combine1(st[0],st[1]))));
    }
    //第一步合并
    private static String combine1(String str1,String str2){
        StringBuilder str=new StringBuilder();
        for(char ch:str1.toCharArray())
            str.append(ch);
        for(char ch:str2.toCharArray())
            str.append(ch);
        return str.toString();
    }
    //第二步合并
    private static String combine2(String str){
        char []chs=str.toCharArray();
        //取出偶数位排序
        char []ch2=new char[str.length()/2];
        int j=0;
        for(int i=0;i<str.length();i++){
            if(i%2!=0)
                ch2[j++]=chs[i];
        }
        Arrays.sort(ch2);
        //取出奇数位排序
        char []ch1=new char[str.length()-str.length()/2];
        int k=0;
        for(int i=0;i<str.length();i++)
            if(i%2==0)
                ch1[k++]=chs[i];
        Arrays.sort(ch1);
        StringBuilder str1=new StringBuilder();
        for(int i=0;i<str.length();i++){
            if(i%2==0)
                str1.append(ch1[i/2]);
            else
                str1.append(ch2[i/2]);
        }
        return str1.toString();
    }
    //调整阶段
    private static String adjust(String str){
        StringBuilder ans=new StringBuilder();
        char []chs=str.toCharArray();
        for(char ch:chs){
            if(!((ch>=48&&ch<=57)||(ch>=65&&ch<=70)||(ch>=97&&ch<=102))){
                ans.append(ch);
                continue;
            }
            int temp=0;
            if((ch>=65&&ch<=70)||(ch>=97&&ch<=102))
                //16进制转10进制
                temp=Integer.parseInt(String.valueOf(ch),16);
            else
                temp=Integer.parseInt(String.valueOf(ch));
            //10进制转4位二进制
            String temp_=Integer.toString(temp,2);
            String temp__=String.format("%4s",temp_).replace(' ','0');
            //反转二进制
            StringBuilder reversed=new StringBuilder();
            for(int i=3;i>=0;i--){
                reversed.append(temp__.charAt(i));
            }
            //二进制转16进制
            int temp___=Integer.parseInt(reversed.toString(),2);
            String hex=Integer.toString(temp___,16);
            //转成大写
            String heX=hex.toUpperCase();
            ans.append(heX);
        }
        return ans.toString();
    }
}