题解 | #统计字符#

import java.util.Scanner;

// 注意类名必须为 Main, 不要有任何 package xxx 信息
public class Main {

    private static int w_count = 0; 
    private static int s_count = 0; 
    private static int n_count = 0; 
    private static int o_count = 0; 

    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        // 注意 hasNext 和 hasNextLine 的区别
        while (in.hasNextLine()) { // 注意 while 处理多个 case
            String s = in.nextLine();
            count(s);
        }
        System.out.println(w_count);
        System.out.println(s_count);
        System.out.println(n_count);
        System.out.println(o_count);

    }

    private static void count(String s){
        int len = s.length();
        for(int i=0;i<len;i++){
            char c = s.charAt(i);
            if(c >= '0' && c<='9'){
                n_count +=1;
            } else if (c == ' '){
                s_count +=1;
            } else if(c >= 'A' && c<= 'Z'){
                w_count +=1;
            } else if(c >= 'a' && c<= 'z'){
                w_count +=1;
            } else{
                o_count +=1;
            }
        }
    }

}