关于eof

心已赠人 2022-05-24 13:35 187阅读 0赞

今天首次注册了杭电的账号，转变一下自己的咸鱼生活。

找了最简单的一道题不出所料遇到了困难。内容如下：

<table style="color:rgb(0,0,0);font-family:'Times New Roman';font-size:14px;text-align:center;"> 
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    <div style="height:38px;background:transparent url(&quot;/images/panel-title.PNG&quot;) no-repeat center bottom;padding:0px 14px;color:rgb(124,169,237);font-size:18px;font-family:Arial;font-weight:bold;margin:auto;">
      Problem Description 
    </div> 
    <div style="height:auto;background:url(&quot;/images/panel-content.png&quot;) repeat-y center;margin:auto;padding:0px 20px;font-family:'Times New Roman';">
      Your task is to Calculate a + b. 
     <br>Too easy?! Of course! I specially designed the problem for acm beginners.&nbsp; 
     <br>You must have found that some problems have the same titles with this one, yes, all these problems were designed for the same aim.&nbsp; 
     <br> 
    </div> 
    <div style="height:auto;margin:auto;background:url(&quot;/images/panel-bottom.png&quot;) no-repeat center top;">
      &nbsp; 
    </div></td> 
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    <div style="height:38px;background:transparent url(&quot;/images/panel-title.PNG&quot;) no-repeat center bottom;padding:0px 14px;color:rgb(124,169,237);font-size:18px;font-family:Arial;font-weight:bold;margin:auto;">
      Input 
    </div> 
    <div style="height:auto;background:url(&quot;/images/panel-content.png&quot;) repeat-y center;margin:auto;padding:0px 20px;font-family:'Times New Roman';">
      The input will consist of a series of pairs of integers a and b, separated by a space, one pair of integers per line.&nbsp; 
     <br> 
    </div> 
    <div style="height:auto;margin:auto;background:url(&quot;/images/panel-bottom.png&quot;) no-repeat center top;">
      &nbsp; 
    </div></td> 
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    <div style="height:38px;background:transparent url(&quot;/images/panel-title.PNG&quot;) no-repeat center bottom;padding:0px 14px;color:rgb(124,169,237);font-size:18px;font-family:Arial;font-weight:bold;margin:auto;">
      Output 
    </div> 
    <div style="height:auto;background:url(&quot;/images/panel-content.png&quot;) repeat-y center;margin:auto;padding:0px 20px;font-family:'Times New Roman';">
      For each pair of input integers a and b you should output the sum of a and b in one line, and with one line of output for each line in input.&nbsp; 
     <br> 
    </div> 
    <div style="height:auto;margin:auto;background:url(&quot;/images/panel-bottom.png&quot;) no-repeat center top;">
      &nbsp; 
    </div></td> 
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    <div style="height:38px;background:transparent url(&quot;/images/panel-title.PNG&quot;) no-repeat center bottom;padding:0px 14px;color:rgb(124,169,237);font-size:18px;font-family:Arial;font-weight:bold;margin:auto;">
      Sample Input 
    </div> 
    <div style="height:auto;background:url(&quot;/images/panel-content.png&quot;) repeat-y center;margin:auto;padding:0px 20px;font-family:'Times New Roman';"> 
     <pre style="margin-bottom:0px;font-size:14px;font-family:'Courier New', Courier, monospace;">1 5
10 20</pre> 
    </div> 
    <div style="height:auto;margin:auto;background:url(&quot;/images/panel-bottom.png&quot;) no-repeat center top;">
      &nbsp; 
    </div></td> 
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    <div style="height:38px;background:transparent url(&quot;/images/panel-title.PNG&quot;) no-repeat center bottom;padding:0px 14px;color:rgb(124,169,237);font-size:18px;font-family:Arial;font-weight:bold;margin:auto;">
      Sample Output 
    </div> 
    <div style="height:auto;background:url(&quot;/images/panel-content.png&quot;) repeat-y center;margin:auto;padding:0px 20px;font-family:'Times New Roman';"> 
     <pre style="margin-bottom:0px;font-size:14px;font-family:'Courier New', Courier, monospace;">6
30</pre> 
    </div></td> 
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 </tbody> 
</table>

首先，我用自己的程序做题时wrong answer

\#include<stdio.h>  
int main() \{  
  int a, b ,sum ,i;  
  for(i=0;i<2;i++)\{  
    scanf("%d %d",&a,&b);  
  printf("%d\\n",a+b);  
  \}   
  return 0;

看似没问题，但是有个循环输入不符题意，所以：

\[cpp\]  [view plain][]   [copy][view plain]

1.  \#include <stdio.h>  
2.  **int** main()  
3.  \{  
4.      **int** a,b;  
5.      **while**(scanf("%d%d",&a,&b)!=EOF)  
6.      \{  
7.          printf("%d\\n",a+b);  
8.      \}  
9.      **return** 0;  
10. \}  
11.

大神的结果是这样的。   EOF它的含义是end of file ，是判断你什么时候输完了以退出循环，一般是Ctrl+z +回车键，按ctrl+Z的时候，进程会关闭标准输入，没有内容可以输入了，返回-1。也就是EOF，此时退出循环，

[view plain]: https://blog.csdn.net/zyw0713/article/details/47107509#