PAT——1010. 一元多项式求导

 1 package com.hone.basical;
 2 
 3 import java.util.Scanner;
 4 /**
 5  * 
 6  * @author Xia
 7  * 合理的利用标记flag,判断是否有输出
 8  */
 9 public class basicalLevel1010Derivative2 {
10     public static void main(String[] args) {
11         Scanner in = new Scanner(System.in);
12         boolean isHaveOutput = false;
13         while (in.hasNext()) {
14             int expon = in.nextInt();
15             int coef = in.nextInt();
16             
17             if (expon * coef != 0) {
18                 if (isHaveOutput) {
19                     System.out.print(" ");
20                 } else {
21                     isHaveOutput = true;
22                 }
23                 System.out.print(expon * coef + " " + (coef - 1));
24             }
25         }
26         in.close();
27         
28         if (!isHaveOutput) {
29             System.out.print("0 0");
30         }
31     }
32 }