数学表达式求值

骑猪看日落 2022-06-02 08:00 256阅读 0赞

**问题描述**

带有变量的中缀表达式是常见的数学表达式。如果规定变量由长度不超过 8 个小写字母组成；end为保留字，表示程序段结束；用？表示输出指定变量的值，则可以设计出比较复杂的表达式（即一个可顺序执行语句序列）。例如，如果有如下语句段：

**abc=10  
def=8  
c=abc+def  
abc=abc+5-c\*2  
? c  
? abc  
end**

则输出为：

**c=18  
abc=-21**

**注意：**为了简化编程实现，运算符只有＋，－，＊，／ ，%和＾（指数运算），可以处理圆括号（），并假定输入的算术表达式正确。

**要求：**使用栈结构实现。

**输入：**表达式序列

**输出：**全部指定变量的值

表达式中的全部计算结果均为整数。如果在计算过程中出现除数为0的情况，则输出：Divide 0.

**特殊情况说明：**  
在表达式中，如果操作数出现负数（例如-8），则要特别注意。例如：  
10加-8表示为：10+-8。  
10减-8表示为：10--8。

<table style="color:rgb(68,68,68); font-size:13px; line-height:25px; width:1615px; margin-bottom:20px; background-color:transparent"> 
 <thead> 
 <tr> 
 <th style="padding:4px; line-height:20px; vertical-align:bottom; border-top-width:0px"> &nbsp;</th> 
 <th style="padding:4px; line-height:20px; vertical-align:bottom; border-top-width:0px"> 测试输入<a href="http://online.bit.edu.cn/moodle/help.php?component=programming&amp;identifier=input&amp;lang=zh_cn" title="关于“测试输入”的帮助" style="color:rgb(67,142,185)" rel="nofollow"><img src="http://online.bit.edu.cn/moodle/theme/image.php/lambda/core/1510491239/help" alt="关于“测试输入”的帮助" style="vertical-align:text-bottom; border:0px; height:16px; padding-left:3px; width:16px"></a></th> 
 <th style="padding:4px; line-height:20px; vertical-align:bottom; border-top-width:0px"> 期待的输出<a href="http://online.bit.edu.cn/moodle/help.php?component=programming&amp;identifier=expectedoutput&amp;lang=zh_cn" title="关于“期待的输出”的帮助" style="color:rgb(67,142,185)" rel="nofollow"><img src="http://online.bit.edu.cn/moodle/theme/image.php/lambda/core/1510491239/help" alt="关于“期待的输出”的帮助" style="vertical-align:text-bottom; border:0px; height:16px; padding-left:3px; width:16px"></a></th> 
 <th style="padding:4px; line-height:20px; vertical-align:bottom; border-top-width:0px"> 时间限制<a href="http://online.bit.edu.cn/moodle/help.php?component=programming&amp;identifier=timelimit&amp;lang=zh_cn" title="关于“时间限制”的帮助" style="color:rgb(67,142,185)" rel="nofollow"><img src="http://online.bit.edu.cn/moodle/theme/image.php/lambda/core/1510491239/help" alt="关于“时间限制”的帮助" style="vertical-align:text-bottom; border:0px; height:16px; padding-left:3px; width:16px"></a></th> 
 <th style="padding:4px; line-height:20px; vertical-align:bottom; border-top-width:0px"> 内存限制<a href="http://online.bit.edu.cn/moodle/help.php?component=programming&amp;identifier=memlimit&amp;lang=zh_cn" title="关于“内存限制”的帮助" style="color:rgb(67,142,185)" rel="nofollow"><img src="http://online.bit.edu.cn/moodle/theme/image.php/lambda/core/1510491239/help" alt="关于“内存限制”的帮助" style="vertical-align:text-bottom; border:0px; height:16px; padding-left:3px; width:16px"></a></th> 
 <th style="padding:4px; line-height:20px; vertical-align:bottom; border-top-width:0px"> 额外进程<a href="http://online.bit.edu.cn/moodle/help.php?component=programming&amp;identifier=nproc&amp;lang=zh_cn" title="关于“{$a} 个额外进程”的帮助" style="color:rgb(67,142,185)" rel="nofollow"><img src="http://online.bit.edu.cn/moodle/theme/image.php/lambda/core/1510491239/help" alt="关于“{$a} 个额外进程”的帮助" style="vertical-align:text-bottom; border:0px; height:16px; padding-left:3px; width:16px"></a></th> 
 </tr> 
 </thead> 
 <tbody> 
 <tr> 
 <td style="padding:4px; line-height:20px; vertical-align:middle; background-color:rgb(249,249,249)"> 测试用例 1</td> 
 <td style="padding:4px; line-height:20px; vertical-align:middle; background-color:rgb(249,249,249)"> <a href="http://online.bit.edu.cn/moodle/mod/programming/testcase/download_io.php?id=64758&amp;test=82450&amp;type=in&amp;download=0" style="color:rgb(67,142,185); font-size:9pt" rel="nofollow">以文本方式显示</a> 
 <div style="vertical-align:top; padding:0px 5px 0px 0px; width:10em; height:10em; overflow:auto"> 
 <ol style="padding-left:0px; margin-bottom:0px; margin-left:2.5em; overflow:visible"> 
 <li style="line-height:20px; font-family:Consolas,'Courier New',Courier,mono,serif; margin:0px; padding:0px; overflow:visible"> abc=10↵</li> 
 <li style="line-height:20px; font-family:Consolas,'Courier New',Courier,mono,serif; margin:0px; padding:0px; overflow:visible"> def=8↵</li> 
 <li style="line-height:20px; font-family:Consolas,'Courier New',Courier,mono,serif; margin:0px; padding:0px; overflow:visible"> c=abc+def↵</li> 
 <li style="line-height:20px; font-family:Consolas,'Courier New',Courier,mono,serif; margin:0px; padding:0px; overflow:visible"> abc=abc+5-c*2↵</li> 
 <li style="line-height:20px; font-family:Consolas,'Courier New',Courier,mono,serif; margin:0px; padding:0px; overflow:visible"> ?&nbsp;c↵</li> 
 <li style="line-height:20px; font-family:Consolas,'Courier New',Courier,mono,serif; margin:0px; padding:0px; overflow:visible"> ?&nbsp;abc↵</li> 
 <li style="line-height:20px; font-family:Consolas,'Courier New',Courier,mono,serif; margin:0px; padding:0px; overflow:visible"> end↵</li> 
 </ol> 
 </div> </td> 
 <td style="padding:4px; line-height:20px; vertical-align:middle; background-color:rgb(249,249,249)"> <a href="http://online.bit.edu.cn/moodle/mod/programming/testcase/download_io.php?id=64758&amp;test=82450&amp;type=out&amp;download=0" style="color:rgb(67,142,185); font-size:9pt" rel="nofollow">以文本方式显示</a> 
 <div style="vertical-align:top; padding:0px 5px 0px 0px; width:10em; height:10em; overflow:auto"> 
 <ol style="padding-left:0px; margin-bottom:0px; margin-left:2.5em; overflow:visible"> 
 <li style="line-height:20px; font-family:Consolas,'Courier New',Courier,mono,serif; margin:0px; padding:0px; overflow:visible"> c=18↵</li> 
 <li style="line-height:20px; font-family:Consolas,'Courier New',Courier,mono,serif; margin:0px; padding:0px; overflow:visible"> abc=-21↵</li> 
 </ol> 
 </div> </td> 
 <td style="padding:4px; line-height:20px; vertical-align:middle; background-color:rgb(249,249,249)"> 1秒</td> 
 <td style="padding:4px; line-height:20px; vertical-align:middle; background-color:rgb(249,249,249)"> 64M</td> 
 <td style="padding:4px; line-height:20px; vertical-align:middle; background-color:rgb(249,249,249)"> 0</td> 
 </tr> 
 <tr> 
 <td style="padding:4px; line-height:20px; vertical-align:middle"> 测试用例 2</td> 
 <td style="padding:4px; line-height:20px; vertical-align:middle"> <a href="http://online.bit.edu.cn/moodle/mod/programming/testcase/download_io.php?id=64758&amp;test=82455&amp;type=in&amp;download=0" style="color:rgb(67,142,185); font-size:9pt" rel="nofollow">以文本方式显示</a> 
 <div style="vertical-align:top; padding:0px 5px 0px 0px; width:10em; height:10em; overflow:auto"> 
 <ol style="padding-left:0px; margin-bottom:0px; margin-left:2.5em; overflow:visible"> 
 <li style="line-height:20px; font-family:Consolas,'Courier New',Courier,mono,serif; margin:0px; padding:0px; overflow:visible"> a=12↵</li> 
 <li style="line-height:20px; font-family:Consolas,'Courier New',Courier,mono,serif; margin:0px; padding:0px; overflow:visible"> b=5↵</li> 
 <li style="line-height:20px; font-family:Consolas,'Courier New',Courier,mono,serif; margin:0px; padding:0px; overflow:visible"> c=a/b↵</li> 
 <li style="line-height:20px; font-family:Consolas,'Courier New',Courier,mono,serif; margin:0px; padding:0px; overflow:visible"> d=(a+1)%(b+1)↵</li> 
 <li style="line-height:20px; font-family:Consolas,'Courier New',Courier,mono,serif; margin:0px; padding:0px; overflow:visible"> e=a^2↵</li> 
 <li style="line-height:20px; font-family:Consolas,'Courier New',Courier,mono,serif; margin:0px; padding:0px; overflow:visible"> f=-12+a↵</li> 
 <li style="line-height:20px; font-family:Consolas,'Courier New',Courier,mono,serif; margin:0px; padding:0px; overflow:visible"> g=(a+5)*d-c↵</li> 
 <li style="line-height:20px; font-family:Consolas,'Courier New',Courier,mono,serif; margin:0px; padding:0px; overflow:visible"> ?&nbsp;c↵</li> 
 <li style="line-height:20px; font-family:Consolas,'Courier New',Courier,mono,serif; margin:0px; padding:0px; overflow:visible"> ?&nbsp;d↵</li> 
 <li style="line-height:20px; font-family:Consolas,'Courier New',Courier,mono,serif; margin:0px; padding:0px; overflow:visible"> ?&nbsp;e↵</li> 
 <li style="line-height:20px; font-family:Consolas,'Courier New',Courier,mono,serif; margin:0px; padding:0px; overflow:visible"> ?&nbsp;f↵</li> 
 <li style="line-height:20px; font-family:Consolas,'Courier New',Courier,mono,serif; margin:0px; padding:0px; overflow:visible"> ?&nbsp;g↵</li> 
 <li style="line-height:20px; font-family:Consolas,'Courier New',Courier,mono,serif; margin:0px; padding:0px; overflow:visible"> a=a+10↵</li> 
 <li style="line-height:20px; font-family:Consolas,'Courier New',Courier,mono,serif; margin:0px; padding:0px; overflow:visible"> ?&nbsp;a↵</li> 
 <li style="line-height:20px; font-family:Consolas,'Courier New',Courier,mono,serif; margin:0px; padding:0px; overflow:visible"> end↵</li> 
 </ol> 
 </div> </td> 
 <td style="padding:4px; line-height:20px; vertical-align:middle"> <a href="http://online.bit.edu.cn/moodle/mod/programming/testcase/download_io.php?id=64758&amp;test=82455&amp;type=out&amp;download=0" style="color:rgb(67,142,185); font-size:9pt" rel="nofollow">以文本方式显示</a> 
 <div style="vertical-align:top; padding:0px 5px 0px 0px; width:10em; height:10em; overflow:auto"> 
 <ol style="padding-left:0px; margin-bottom:0px; margin-left:2.5em; overflow:visible"> 
 <li style="line-height:20px; font-family:Consolas,'Courier New',Courier,mono,serif; margin:0px; padding:0px; overflow:visible"> c=2↵</li> 
 <li style="line-height:20px; font-family:Consolas,'Courier New',Courier,mono,serif; margin:0px; padding:0px; overflow:visible"> d=1↵</li> 
 <li style="line-height:20px; font-family:Consolas,'Courier New',Courier,mono,serif; margin:0px; padding:0px; overflow:visible"> e=144↵</li> 
 <li style="line-height:20px; font-family:Consolas,'Courier New',Courier,mono,serif; margin:0px; padding:0px; overflow:visible"> f=0↵</li> 
 <li style="line-height:20px; font-family:Consolas,'Courier New',Courier,mono,serif; margin:0px; padding:0px; overflow:visible"> g=15↵</li> 
 <li style="line-height:20px; font-family:Consolas,'Courier New',Courier,mono,serif; margin:0px; padding:0px; overflow:visible"> a=22↵</li> 
 </ol> 
 </div> </td> 
 <td style="padding:4px; line-height:20px; vertical-align:middle"> 1秒</td> 
 <td style="padding:4px; line-height:20px; vertical-align:middle"> 64M</td> 
 <td style="padding:4px; line-height:20px; vertical-align:middle"> 0</td> 
 </tr> 
 <tr> 
 <td style="padding:4px; line-height:20px; vertical-align:middle; background-color:rgb(249,249,249)"> 测试用例 3</td> 
 <td style="padding:4px; line-height:20px; vertical-align:middle; background-color:rgb(249,249,249)"> <a href="http://online.bit.edu.cn/moodle/mod/programming/testcase/download_io.php?id=64758&amp;test=82451&amp;type=in&amp;download=0" style="color:rgb(67,142,185); font-size:9pt" rel="nofollow">以文本方式显示</a> 
 <div style="vertical-align:top; padding:0px 5px 0px 0px; width:10em; height:10em; overflow:auto"> 
 <ol style="padding-left:0px; margin-bottom:0px; margin-left:2.5em; overflow:visible"> 
 <li style="line-height:20px; font-family:Consolas,'Courier New',Courier,mono,serif; margin:0px; padding:0px; overflow:visible"> abc=3↵</li> 
 <li style="line-height:20px; font-family:Consolas,'Courier New',Courier,mono,serif; margin:0px; padding:0px; overflow:visible"> ab=2^(abc-1)^(5-abc)↵</li> 
 <li style="line-height:20px; font-family:Consolas,'Courier New',Courier,mono,serif; margin:0px; padding:0px; overflow:visible"> ?&nbsp;ab↵</li> 
 <li style="line-height:20px; font-family:Consolas,'Courier New',Courier,mono,serif; margin:0px; padding:0px; overflow:visible"> end↵</li> 
 </ol> 
 </div> </td> 
 <td style="padding:4px; line-height:20px; vertical-align:middle; background-color:rgb(249,249,249)"> <a href="http://online.bit.edu.cn/moodle/mod/programming/testcase/download_io.php?id=64758&amp;test=82451&amp;type=out&amp;download=0" style="color:rgb(67,142,185); font-size:9pt" rel="nofollow">以文本方式显示</a> 
 <div style="vertical-align:top; padding:0px 5px 0px 0px; width:10em; height:10em; overflow:auto"> 
 <ol style="padding-left:0px; margin-bottom:0px; margin-left:2.5em; overflow:visible"> 
 <li style="line-height:20px; font-family:Consolas,'Courier New',Courier,mono,serif; margin:0px; padding:0px; overflow:visible"> ab=16↵</li> 
 </ol> 
 </div> </td> 
 <td style="padding:4px; line-height:20px; vertical-align:middle; background-color:rgb(249,249,249)"> 1秒</td> 
 <td style="padding:4px; line-height:20px; vertical-align:middle; background-color:rgb(249,249,249)"> 64M</td> 
 <td style="padding:4px; line-height:20px; vertical-align:middle; background-color:rgb(249,249,249)"> 0</td> 
 </tr> 
 <tr> 
 <td style="padding:4px; line-height:20px; vertical-align:middle"> 测试用例 4</td> 
 <td style="padding:4px; line-height:20px; vertical-align:middle"> <a href="http://online.bit.edu.cn/moodle/mod/programming/testcase/download_io.php?id=64758&amp;test=82452&amp;type=in&amp;download=0" style="color:rgb(67,142,185); font-size:9pt" rel="nofollow">以文本方式显示</a> 
 <div style="vertical-align:top; padding:0px 5px 0px 0px; width:10em; height:10em; overflow:auto"> 
 <ol style="padding-left:0px; margin-bottom:0px; margin-left:2.5em; overflow:visible"> 
 <li style="line-height:20px; font-family:Consolas,'Courier New',Courier,mono,serif; margin:0px; padding:0px; overflow:visible"> a=2↵</li> 
 <li style="line-height:20px; font-family:Consolas,'Courier New',Courier,mono,serif; margin:0px; padding:0px; overflow:visible"> b=a^(a+1)^(10-8)↵</li> 
 <li style="line-height:20px; font-family:Consolas,'Courier New',Courier,mono,serif; margin:0px; padding:0px; overflow:visible"> ?&nbsp;b↵</li> 
 <li style="line-height:20px; font-family:Consolas,'Courier New',Courier,mono,serif; margin:0px; padding:0px; overflow:visible"> end↵</li> 
 </ol> 
 </div> </td> 
 <td style="padding:4px; line-height:20px; vertical-align:middle"> <a href="http://online.bit.edu.cn/moodle/mod/programming/testcase/download_io.php?id=64758&amp;test=82452&amp;type=out&amp;download=0" style="color:rgb(67,142,185); font-size:9pt" rel="nofollow">以文本方式显示</a> 
 <div style="vertical-align:top; padding:0px 5px 0px 0px; width:10em; height:10em; overflow:auto"> 
 <ol style="padding-left:0px; margin-bottom:0px; margin-left:2.5em; overflow:visible"> 
 <li style="line-height:20px; font-family:Consolas,'Courier New',Courier,mono,serif; margin:0px; padding:0px; overflow:visible"> b=512↵</li> 
 </ol> 
 </div> </td> 
 <td style="padding:4px; line-height:20px; vertical-align:middle"> 1秒</td> 
 <td style="padding:4px; line-height:20px; vertical-align:middle"> 64M</td> 
 <td style="padding:4px; line-height:20px; vertical-align:middle"> 0</td> 
 </tr> 
 <tr> 
 <td style="padding:4px; line-height:20px; vertical-align:middle; background-color:rgb(249,249,249)"> 测试用例 5</td> 
 <td style="padding:4px; line-height:20px; vertical-align:middle; background-color:rgb(249,249,249)"> <a href="http://online.bit.edu.cn/moodle/mod/programming/testcase/download_io.php?id=64758&amp;test=82453&amp;type=in&amp;download=0" style="color:rgb(67,142,185); font-size:9pt" rel="nofollow">以文本方式显示</a> 
 <div style="vertical-align:top; padding:0px 5px 0px 0px; width:10em; height:10em; overflow:auto"> 
 <ol style="padding-left:0px; margin-bottom:0px; margin-left:2.5em; overflow:visible"> 
 <li style="line-height:20px; font-family:Consolas,'Courier New',Courier,mono,serif; margin:0px; padding:0px; overflow:visible"> a=10↵</li> 
 <li style="line-height:20px; font-family:Consolas,'Courier New',Courier,mono,serif; margin:0px; padding:0px; overflow:visible"> ?&nbsp;a↵</li> 
 <li style="line-height:20px; font-family:Consolas,'Courier New',Courier,mono,serif; margin:0px; padding:0px; overflow:visible"> b=-10+10↵</li> 
 <li style="line-height:20px; font-family:Consolas,'Courier New',Courier,mono,serif; margin:0px; padding:0px; overflow:visible"> ?&nbsp;b↵</li> 
 <li style="line-height:20px; font-family:Consolas,'Courier New',Courier,mono,serif; margin:0px; padding:0px; overflow:visible"> a=-10-10↵</li> 
 <li style="line-height:20px; font-family:Consolas,'Courier New',Courier,mono,serif; margin:0px; padding:0px; overflow:visible"> ?&nbsp;a↵</li> 
 <li style="line-height:20px; font-family:Consolas,'Courier New',Courier,mono,serif; margin:0px; padding:0px; overflow:visible"> c=a+-10+-10↵</li> 
 <li style="line-height:20px; font-family:Consolas,'Courier New',Courier,mono,serif; margin:0px; padding:0px; overflow:visible"> ?&nbsp;c↵</li> 
 <li style="line-height:20px; font-family:Consolas,'Courier New',Courier,mono,serif; margin:0px; padding:0px; overflow:visible"> d=-20+-8-8↵</li> 
 <li style="line-height:20px; font-family:Consolas,'Courier New',Courier,mono,serif; margin:0px; padding:0px; overflow:visible"> ?&nbsp;d↵</li> 
 <li style="line-height:20px; font-family:Consolas,'Courier New',Courier,mono,serif; margin:0px; padding:0px; overflow:visible"> e=a-12*-2↵</li> 
 <li style="line-height:20px; font-family:Consolas,'Courier New',Courier,mono,serif; margin:0px; padding:0px; overflow:visible"> ?&nbsp;e↵</li> 
 <li style="line-height:20px; font-family:Consolas,'Courier New',Courier,mono,serif; margin:0px; padding:0px; overflow:visible"> f=80--10+2↵</li> 
 <li style="line-height:20px; font-family:Consolas,'Courier New',Courier,mono,serif; margin:0px; padding:0px; overflow:visible"> ?&nbsp;f↵</li> 
 <li style="line-height:20px; font-family:Consolas,'Courier New',Courier,mono,serif; margin:0px; padding:0px; overflow:visible"> g=-10--10↵</li> 
 <li style="line-height:20px; font-family:Consolas,'Courier New',Courier,mono,serif; margin:0px; padding:0px; overflow:visible"> ?&nbsp;g↵</li> 
 <li style="line-height:20px; font-family:Consolas,'Courier New',Courier,mono,serif; margin:0px; padding:0px; overflow:visible"> h=-10+-10↵</li> 
 <li style="line-height:20px; font-family:Consolas,'Courier New',Courier,mono,serif; margin:0px; padding:0px; overflow:visible"> ?&nbsp;h↵</li> 
 <li style="line-height:20px; font-family:Consolas,'Courier New',Courier,mono,serif; margin:0px; padding:0px; overflow:visible"> i=(90)↵</li> 
 <li style="line-height:20px; font-family:Consolas,'Courier New',Courier,mono,serif; margin:0px; padding:0px; overflow:visible"> ?&nbsp;i↵</li> 
 <li style="line-height:20px; font-family:Consolas,'Courier New',Courier,mono,serif; margin:0px; padding:0px; overflow:visible"> k=(-100)↵</li> 
 <li style="line-height:20px; font-family:Consolas,'Courier New',Courier,mono,serif; margin:0px; padding:0px; overflow:visible"> ?&nbsp;k↵</li> 
 <li style="line-height:20px; font-family:Consolas,'Courier New',Courier,mono,serif; margin:0px; padding:0px; overflow:visible"> end↵</li> 
 </ol> 
 </div> </td> 
 <td style="padding:4px; line-height:20px; vertical-align:middle; background-color:rgb(249,249,249)"> <a href="http://online.bit.edu.cn/moodle/mod/programming/testcase/download_io.php?id=64758&amp;test=82453&amp;type=out&amp;download=0" style="color:rgb(67,142,185); font-size:9pt" rel="nofollow">以文本方式显示</a> 
 <div style="vertical-align:top; padding:0px 5px 0px 0px; width:10em; height:10em; overflow:auto"> 
 <ol style="padding-left:0px; margin-bottom:0px; margin-left:2.5em; overflow:visible"> 
 <li style="line-height:20px; font-family:Consolas,'Courier New',Courier,mono,serif; margin:0px; padding:0px; overflow:visible"> a=10↵</li> 
 <li style="line-height:20px; font-family:Consolas,'Courier New',Courier,mono,serif; margin:0px; padding:0px; overflow:visible"> b=0↵</li> 
 <li style="line-height:20px; font-family:Consolas,'Courier New',Courier,mono,serif; margin:0px; padding:0px; overflow:visible"> a=-20↵</li> 
 <li style="line-height:20px; font-family:Consolas,'Courier New',Courier,mono,serif; margin:0px; padding:0px; overflow:visible"> c=-40↵</li> 
 <li style="line-height:20px; font-family:Consolas,'Courier New',Courier,mono,serif; margin:0px; padding:0px; overflow:visible"> d=-36↵</li> 
 <li style="line-height:20px; font-family:Consolas,'Courier New',Courier,mono,serif; margin:0px; padding:0px; overflow:visible"> e=4↵</li> 
 <li style="line-height:20px; font-family:Consolas,'Courier New',Courier,mono,serif; margin:0px; padding:0px; overflow:visible"> f=92↵</li> 
 <li style="line-height:20px; font-family:Consolas,'Courier New',Courier,mono,serif; margin:0px; padding:0px; overflow:visible"> g=0↵</li> 
 <li style="line-height:20px; font-family:Consolas,'Courier New',Courier,mono,serif; margin:0px; padding:0px; overflow:visible"> h=-20↵</li> 
 <li style="line-height:20px; font-family:Consolas,'Courier New',Courier,mono,serif; margin:0px; padding:0px; overflow:visible"> i=90↵</li> 
 <li style="line-height:20px; font-family:Consolas,'Courier New',Courier,mono,serif; margin:0px; padding:0px; overflow:visible"> k=-100↵</li> 
 </ol> 
 </div> </td> 
 <td style="padding:4px; line-height:20px; vertical-align:middle; background-color:rgb(249,249,249)"> 1秒</td> 
 <td style="padding:4px; line-height:20px; vertical-align:middle; background-color:rgb(249,249,249)"> 64M</td> 
 <td style="padding:4px; line-height:20px; vertical-align:middle; background-color:rgb(249,249,249)"> 0</td> 
 </tr> 
 <tr> 
 <td style="padding:4px; line-height:20px; vertical-align:middle"> 测试用例 6</td> 
 <td style="padding:4px; line-height:20px; vertical-align:middle"> <a href="http://online.bit.edu.cn/moodle/mod/programming/testcase/download_io.php?id=64758&amp;test=82454&amp;type=in&amp;download=0" style="color:rgb(67,142,185); font-size:9pt" rel="nofollow">以文本方式显示</a> 
 <div style="vertical-align:top; padding:0px 5px 0px 0px; width:10em; height:10em; overflow:auto"> 
 <ol style="padding-left:0px; margin-bottom:0px; margin-left:2.5em; overflow:visible"> 
 <li style="line-height:20px; font-family:Consolas,'Courier New',Courier,mono,serif; margin:0px; padding:0px; overflow:visible"> abcdefgh=4↵</li> 
 <li style="line-height:20px; font-family:Consolas,'Courier New',Courier,mono,serif; margin:0px; padding:0px; overflow:visible"> ten=10↵</li> 
 <li style="line-height:20px; font-family:Consolas,'Courier New',Courier,mono,serif; margin:0px; padding:0px; overflow:visible"> a=18-32↵</li> 
 <li style="line-height:20px; font-family:Consolas,'Courier New',Courier,mono,serif; margin:0px; padding:0px; overflow:visible"> ?&nbsp;a↵</li> 
 <li style="line-height:20px; font-family:Consolas,'Courier New',Courier,mono,serif; margin:0px; padding:0px; overflow:visible"> b=18/abcdefgh↵</li> 
 <li style="line-height:20px; font-family:Consolas,'Courier New',Courier,mono,serif; margin:0px; padding:0px; overflow:visible"> ?&nbsp;b↵</li> 
 <li style="line-height:20px; font-family:Consolas,'Courier New',Courier,mono,serif; margin:0px; padding:0px; overflow:visible"> c=18%(b-1)↵</li> 
 <li style="line-height:20px; font-family:Consolas,'Courier New',Courier,mono,serif; margin:0px; padding:0px; overflow:visible"> ?&nbsp;c↵</li> 
 <li style="line-height:20px; font-family:Consolas,'Courier New',Courier,mono,serif; margin:0px; padding:0px; overflow:visible"> d=ten+(ten+ten)*abcdefgh↵</li> 
 <li style="line-height:20px; font-family:Consolas,'Courier New',Courier,mono,serif; margin:0px; padding:0px; overflow:visible"> ?&nbsp;d↵</li> 
 <li style="line-height:20px; font-family:Consolas,'Courier New',Courier,mono,serif; margin:0px; padding:0px; overflow:visible"> e=ten-2*ten/abcdefgh↵</li> 
 <li style="line-height:20px; font-family:Consolas,'Courier New',Courier,mono,serif; margin:0px; padding:0px; overflow:visible"> ?&nbsp;e↵</li> 
 <li style="line-height:20px; font-family:Consolas,'Courier New',Courier,mono,serif; margin:0px; padding:0px; overflow:visible"> f=(18-3)*3↵</li> 
 <li style="line-height:20px; font-family:Consolas,'Courier New',Courier,mono,serif; margin:0px; padding:0px; overflow:visible"> ?&nbsp;f↵</li> 
 <li style="line-height:20px; font-family:Consolas,'Courier New',Courier,mono,serif; margin:0px; padding:0px; overflow:visible"> ten=ten*(ten)↵</li> 
 <li style="line-height:20px; font-family:Consolas,'Courier New',Courier,mono,serif; margin:0px; padding:0px; overflow:visible"> ?&nbsp;ten↵</li> 
 <li style="line-height:20px; font-family:Consolas,'Courier New',Courier,mono,serif; margin:0px; padding:0px; overflow:visible"> ten=ten/10↵</li> 
 <li style="line-height:20px; font-family:Consolas,'Courier New',Courier,mono,serif; margin:0px; padding:0px; overflow:visible"> ten=(ten+2)/(8-ten)↵</li> 
 <li style="line-height:20px; font-family:Consolas,'Courier New',Courier,mono,serif; margin:0px; padding:0px; overflow:visible"> ?&nbsp;ten↵</li> 
 <li style="line-height:20px; font-family:Consolas,'Courier New',Courier,mono,serif; margin:0px; padding:0px; overflow:visible"> h=(2*3)/(5*2)↵</li> 
 <li style="line-height:20px; font-family:Consolas,'Courier New',Courier,mono,serif; margin:0px; padding:0px; overflow:visible"> ?&nbsp;h↵</li> 
 <li style="line-height:20px; font-family:Consolas,'Courier New',Courier,mono,serif; margin:0px; padding:0px; overflow:visible"> ten=10↵</li> 
 <li style="line-height:20px; font-family:Consolas,'Courier New',Courier,mono,serif; margin:0px; padding:0px; overflow:visible"> x=ten-(80-30)/3*3+abcdefgh↵</li> 
 <li style="line-height:20px; font-family:Consolas,'Courier New',Courier,mono,serif; margin:0px; padding:0px; overflow:visible"> y=(((2+8)*2-(2+abcdefgh)/2)*2-8)*2↵</li> 
 <li style="line-height:20px; font-family:Consolas,'Courier New',Courier,mono,serif; margin:0px; padding:0px; overflow:visible"> z=(((8+2)*(abcdefgh/2)))↵</li> 
 <li style="line-height:20px; font-family:Consolas,'Courier New',Courier,mono,serif; margin:0px; padding:0px; overflow:visible"> ?&nbsp;x↵</li> 
 <li style="line-height:20px; font-family:Consolas,'Courier New',Courier,mono,serif; margin:0px; padding:0px; overflow:visible"> ?&nbsp;y↵</li> 
 <li style="line-height:20px; font-family:Consolas,'Courier New',Courier,mono,serif; margin:0px; padding:0px; overflow:visible"> ?&nbsp;z↵</li> 
 <li style="line-height:20px; font-family:Consolas,'Courier New',Courier,mono,serif; margin:0px; padding:0px; overflow:visible"> end↵</li> 
 </ol> 
 </div> </td> 
 <td style="padding:4px; line-height:20px; vertical-align:middle"> <a href="http://online.bit.edu.cn/moodle/mod/programming/testcase/download_io.php?id=64758&amp;test=82454&amp;type=out&amp;download=0" style="color:rgb(67,142,185); font-size:9pt" rel="nofollow">以文本方式显示</a> 
 <div style="vertical-align:top; padding:0px 5px 0px 0px; width:10em; height:10em; overflow:auto"> 
 <ol style="padding-left:0px; margin-bottom:0px; margin-left:2.5em; overflow:visible"> 
 <li style="line-height:20px; font-family:Consolas,'Courier New',Courier,mono,serif; margin:0px; padding:0px; overflow:visible"> a=-14↵</li> 
 <li style="line-height:20px; font-family:Consolas,'Courier New',Courier,mono,serif; margin:0px; padding:0px; overflow:visible"> b=4↵</li> 
 <li style="line-height:20px; font-family:Consolas,'Courier New',Courier,mono,serif; margin:0px; padding:0px; overflow:visible"> c=0↵</li> 
 <li style="line-height:20px; font-family:Consolas,'Courier New',Courier,mono,serif; margin:0px; padding:0px; overflow:visible"> d=90↵</li> 
 <li style="line-height:20px; font-family:Consolas,'Courier New',Courier,mono,serif; margin:0px; padding:0px; overflow:visible"> e=5↵</li> 
 <li style="line-height:20px; font-family:Consolas,'Courier New',Courier,mono,serif; margin:0px; padding:0px; overflow:visible"> f=45↵</li> 
 <li style="line-height:20px; font-family:Consolas,'Courier New',Courier,mono,serif; margin:0px; padding:0px; overflow:visible"> ten=100↵</li> 
 <li style="line-height:20px; font-family:Consolas,'Courier New',Courier,mono,serif; margin:0px; padding:0px; overflow:visible"> ten=-6↵</li> 
 <li style="line-height:20px; font-family:Consolas,'Courier New',Courier,mono,serif; margin:0px; padding:0px; overflow:visible"> h=0↵</li> 
 <li style="line-height:20px; font-family:Consolas,'Courier New',Courier,mono,serif; margin:0px; padding:0px; overflow:visible"> x=-34↵</li> 
 <li style="line-height:20px; font-family:Consolas,'Courier New',Courier,mono,serif; margin:0px; padding:0px; overflow:visible"> y=52↵</li> 
 <li style="line-height:20px; font-family:Consolas,'Courier New',Courier,mono,serif; margin:0px; padding:0px; overflow:visible"> z=20↵</li> 
 </ol> 
 </div> </td> 
 <td style="padding:4px; line-height:20px; vertical-align:middle"> 1秒</td> 
 <td style="padding:4px; line-height:20px; vertical-align:middle"> 64M</td> 
 <td style="padding:4px; line-height:20px; vertical-align:middle"> 0</td> 
 </tr> 
 </tbody> 
</table>

#include<cstdio> 
 #include<string> 
 #include<map> 
 #include<stack> 
 #include<math.h> 
 #include<iostream> 
 using namespace std; 
 
 map<string, int> Varible; 
 stack<char> Op; 
 stack<int> Opnum; 
 string Instruction; 
 string tmp; 
 
 int GetproiIncoming(char c) //栈外的优先级
 { 
 switch (c) 
 { 
 case('+') : return 3; 
 case('-') : return 3; 
 case('*') : return 5; 
 case('/') : return 5; 
 case('%') : return 5; 
 case('(') : return 10; 
 case('^') : return 8; 
 } 
 } 
 
 int GetproInstack(char c) //栈内的优先级
 { 
 switch (c) 
 { 
 case('+') : return 4; 
 case('-') : return 4; 
 case('*') : return 6; 
 case('/') : return 6; 
 case('%') : return 6; 
 case('(') : return 1; 
 case('^') : return 7; 
 } 
 } 
 
 int comput(char c, int a, int b) 
 { 
 switch (c) 
 { 
 case('+') : return a+b; 
 case('-') : return a-b; 
 case('*') : return a*b; 
 case('/') : return a/b; 
 case('%') : return a%b; 
 case('^') : return (int)pow(double(a),double(b)); 
 } 
 } 
 
 int Getvar(string tmp) 
 { 
 int num = 0; 
 for (int i = 0; tmp[i]; i++) 
 { 
 if (tmp[i] >= '0'&&tmp[i] <= '9') 
 { 
 num = num * 10 + tmp[i] - '0'; 
 } 
 else if (tmp[i] >= 'a'&&tmp[i] <= 'z') 
 { 
 string var; 
 int k = i; 
 while (tmp[k] >= 'a'&&tmp[k] <= 'z') 
 { 
 k++; 
 } 
 var = tmp.substr(i, k-i); 
 Opnum.push(Varible[var]); 
 i = k - 1; 
 } 
 else if (!(tmp[i] >= '0'&&tmp[i] <= '9') && !(tmp[i] >= 'a'&&tmp[i] <= 'z')) 
 { 
 if (tmp[i] == '=') continue; 
 if ((tmp[i - 1] >= '0'&&tmp[i - 1] <= '9')) 
 { 
 Opnum.push(num); num = 0; 
 } 
 else if (!(tmp[i - 1] >= '0'&&tmp[i - 1] <= '9') && !(tmp[i - 1] >= 'a'&&tmp[i - 1] <= 'z')&&(tmp[i]=='+'||tmp[i]=='-')) 
 { 
 i++; int k = i; 
 while (tmp[k] && (tmp[k] >= '0'&&tmp[k] <= '9')) 
 { 
 num = num * 10 + tmp[k] - '0'; k++; 
 } 
 if (tmp[i - 1] == '-') num *= -1; i = k - 1; continue; 
 } 
 if (Op.empty()||tmp[i]=='(') 
 { 
 Op.push(tmp[i]); continue; 
 } 
 else if (tmp[i] == ')') 
 { 
 char op; 
 while (!Op.empty() && (op = Op.top()) != '(') 
 { 
 int b = Opnum.top(); Opnum.pop(); 
 int a = Opnum.top(); Opnum.pop(); 
 if (b == 0 && op == '/') 
 continue; 
 else { Opnum.push(comput(op,a,b)); } 
 Op.pop(); 
 } 
 Op.pop(); 
 } 
 else 
 { 
 int Incoming = GetproiIncoming(tmp[i]); 
 int Instack; 
 char op; 
 while (!Op.empty()&&(Instack = GetproInstack(Op.top())) > Incoming) 
 { 
 op = Op.top(); 
 int b = Opnum.top(); Opnum.pop(); 
 int a = Opnum.top(); Opnum.pop(); 
 if (b == 0 && op == '/') 
 continue; 
 else { Opnum.push(comput(op, a, b)); } 
 Op.pop(); 
 } 
 Op.push(tmp[i]); 
 } 
 } 
 } 
 if (tmp[tmp.length()-1] >= '0'&&tmp[tmp.length()-1] <= '9') 
 Opnum.push(num); 
 if (!Op.empty()||!Opnum.empty()) 
 { 
 
 while (!Op.empty()) 
 { 
 char op = Op.top(); 
 int b = Opnum.top(); Opnum.pop(); 
 int a = Opnum.top(); Opnum.pop(); 
 if (b == 0 && op == '/') 
 continue; 
 else { Opnum.push(comput(op, a, b)); } 
 Op.pop(); 
 } 
 return Opnum.top(); 
 } 
 else return num; 
 } 
 int main() 
 { 
 //freopen("1.txt", "r", stdin); 
 while (getline(cin,Instruction)) 
 { 
 if (Instruction == "end") 
 break; 
 while (!Op.empty()) 
 Op.pop(); 
 while (!Opnum.empty()) 
 Opnum.pop(); 
 if (Instruction[0] == '?') 
 { 
 tmp = Instruction.substr(2); 
 int num = Varible.find(tmp)->second; 
 cout << tmp<< '='<<num<< endl; 
 } 
 else if (Instruction[0] >= 'a'&&Instruction[0] <= 'z') 
 { 
 int i = 0; 
 string varble; 
 while (Instruction[i] != '=') 
 { 
 i++; 
 } 
 varble = Instruction.substr(0, i); 
 if (Varible.count(varble) == 0) 
 { 
 Varible[varble] = 0; 
 
 } 
 string tmp = Instruction.substr(i); 
 Varible[varble] = Getvar(tmp); 
 } 
 } 
 return 0; 
 }