zzulioj 1020-1025 java

1023

输入一个字母，为什么不能直接输呢？

还要先变为字符串，后变为字符

import java.util.Scanner;
import java.math.*;
public class demo1 {
    public static void main(String[] args) {
        Scanner input = new Scanner(System.in);
        String ch = input.nextLine();
//        char ch = input.nextLine();
        char r = ch.charAt(0);
        if(r>='a' && r<='z'){
            r = (char)(r-32);
        }
        System.out.println(r);
    }
}

String ch = input.nextLine();

char r = ch.charAt(0);

1025 输入三个字符输出最大的

看不懂

import java.util.*;
public class Main {
    public static void main(String[] args) {
        Scanner cin=new Scanner(System.in);
        String s;int a,b,c;
        s=cin.next();a=s.charAt(0);
        s=cin.next();b=s.charAt(0);
        s=cin.next();c=s.charAt(0);
        if(a>b&&a>c) System.out.printf("%c",a);
        if(b>a&&b>c) System.out.printf("%c",b);
        if(c>a&&c>b) System.out.printf("%c",c);
    }
}

import java.util.*;
public class Main
{
	public static void main(String[] args)
	{
		Scanner input=new Scanner(System.in);
		String ch[]=new String[3];
		ch[0]=input.next();
		ch[1]=input.next();
		ch[2]=input.next();
		String max="";
		if(ch[0].compareTo(ch[1])>0)
			max=ch[0];
		else
			max=ch[1];
		if(max.compareTo(ch[2])<0)
			max=ch[2];
		System.out.println(max);
	}
}