题解 | #数字分类 (20)#

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;

public class Main {

    public static void main(String[] args) throws IOException {
        BufferedReader bf = new BufferedReader(new InputStreamReader(System.in));
        String str = bf.readLine();
        String[] strs = str.split(" ");
        int a1 = 0;
        int a2 = 0;
        int a3 = 0;
        double a4 = 0.0;
        int a5 = 0;
        int count_a2 = 0;   // 符合a2的数字个数
        int count_a4 = 0;   // 符合a4的数字个数
        for(int i = 1 ; i < strs.length ; i++) {
            int num = Integer.parseInt(strs[i]);
            if(num % 5 == 0 ) {
                if(num % 2 == 0) {   // 判定偶数
                    a1 += num;
                }
            } else if(num % 5 == 1) {
                count_a2++;
                // 交错求和
                if(count_a2 % 2 == 0) {
                    a2 -= num;
                } else {
                    a2 += num;
                }
            } else if(num % 5 == 2) {
                a3++;
            } else if(num % 5 == 3) {
                count_a4++;
                a4 += num;
            } else if(num % 5 == 4) {
                if(a5 <= num) {
                    a5 = num;
                }
            }
        }
        if(a4 != 0) {
            a4 = a4 / count_a4;
        }
        if(a1 == 0 ) {
            System.out.print("N ");
        } else {
            System.out.print(a1 + " ");
        }
        if(a2 == 0 && count_a2 == 0) {
            System.out.print("N ");
        } else {
            System.out.print(a2 + " ");
        }
        if(a3 == 0) {
            System.out.print("N ");
        } else {
            System.out.print(a3 + " ");
        }
        if(a4 == 0) {
            System.out.print("N ");
        } else {
            System.out.printf("%.1f",a4);
            System.out.print(" ");
        }
        if(a5 == 0) {
            System.out.print("N");
        } else {
            System.out.println(a5);
        }
    }
}

可以通过pat测试