刷题的狂欢-----JAVA每日三练-----第十九天

第一题

import java.util.Scanner;

public class Main {
          
   
    public static void main(String[] args) {
          
   
        int numbers = 0;
        int words = 0;
        int space = 0;
        int other = 0;
        Scanner scanner = new Scanner(System.in);
        String str = scanner.nextLine();

        int len = str.length();
        for(int i = 0; i<len; i++){
          
   
            if(str.charAt(i)>=a&&str.charAt(i)<=z||str.charAt(i)>=A&&str.charAt(i)<=Z){
          
   
                words++;
            }
            else if(str.charAt(i)>=0&&str.charAt(i)<=9){
          
   
                numbers++;
            }
            else if(str.charAt(i)== ){
          
   
                space++;
            }
            else{
          
   
                other++;
            }
        }
        
        System.out.println("英文字母"+words+"数字"+numbers+"空格"+space+"其他"+other);
    }
}

第二题

import java.util.Scanner;

public class Main {
          
   
    public static void main(String[] args) {
          
   
        Scanner console = new Scanner(System.in);
        Main main = new Main();
        int number = console.nextInt();
        System.out.println(main.palindromeNumber(number));
    }
    public Boolean palindromeNumber(int number){
          
   
        int array[] = new int [5];
        int i;
        for(i=0; i<5; i++){
          
   
            array[i] = number%10;
            number = number/10;
        }

        int j = 0;
        int k = 4;
        while(j<k) {
          
   
            if (array[j++] != array[k--]) {
          
   
                return false;
            } else {
          
   
                return true;
            }
        }
        return null;
    }
}

第三题

import java.util.*;

public class Main {
          
   

    public static void main(String[] args) {
          
   
        LikeRecorder recorder = new LikeRecorderImpl();

        Scanner scanner = new Scanner(System.in);
        while (scanner.hasNext()) {
          
   
            String name = scanner.next();
            recorder.like(name);
        }

        System.out.println(Arrays.toString(recorder.getLikeUsers()));
    }

}

interface LikeRecorder {
          
   

    void like(String username);

    String[] getLikeUsers();

}

class LikeRecorderImpl implements LikeRecorder {
          
   
    private HashSet<String> names = new HashSet();

public void like(String name) {
          
   
    if (names.contains(name)) {
          
   
        names.remove(name);
    } else {
          
   
        names.add(name);
    }
}

public String[] getLikeUsers() {
          
   
    return names.toArray(new String[0]);
}
    
}