为我提供帮助:“空字符常量"；错误. [英] Help me with: "empty character constant" error.

问题描述

// infix.cpp : Defines the entry point for the console application.
//

#include "stdafx.h"
#include<iostream>
#include<string>
#include<stdlib.h>
#include<ctype.h>
using namespace std;

class expression
{
private:
 char infix[100];
 char stack[200];
 int top;
 int r;
 char postfix[100];
public:
 void convert();
 int input_p(char);
 int stack_p(char);
 int rank(char);
};

int expression::input_p(char c)
{
 if( c== ''+'' || c==''-'' )
  return 1;
 else if( c==''*'' || c==''/'' )
  return 3;
 else if( c==''^'')
  return 6;
 else if( isalpha(c)!=0)
  return 7;
 else if( c==''('' )
  return 9;
 else if( c=='')'' )
  return 0;
 else
 {
  cout<<"Invalid expression ::input error\n";
  exit(0);
 }
}

int expression::stack_p(char c)
{
 if(c==''+'' || c==''-'')
  return 2;
 else if(c==''*'' || c==''/'')
  return 4;
 else if(c==''^'' )
  return 5;
 else if(isalpha(c)!=0)
  return 8;
 else if(c== ''('' )
  return 0;
 else
 {
  cout<<"Invalid expression  ::stack error\n";
  exit(0);
 }
}

int expression::rank(char c)
{
 if(c==''+'' || c==''-'')
  return -1;
 else if(c==''*'' || c==''/'')
  return -1;
 else if(c==''^'')
  return -1;
 else if(isalpha(c)!=0)
  return 1;
 else
 {
  cout<<"Invalid expression ::in rank\n";
  exit(0);
 }
}

void expression::convert()
{
 cout<<"\n*************************************************\n"
  <<"This program converts the given infix expression\n"
  <<"in to postfix form"
                <<"\n*************************************************\n";
 cout<<"Enter an infix expression ::\n";
 cin>>infix;
 int l=strlen(infix);

 infix[l]='')'';
 infix[l+1]='''';

 //Convertion starts
 top=1;
 stack[top]=''('';

 r=0;
 int x=-1;

 int i=0;
 char next=infix[i];

 while(next!='''')
 {
  //Pop all the elements to outputin stack which have higher precedence
  while( input_p(next) < stack_p(stack[top]) )
  {
   if(top<1)
   {
    cout<<"invalid expression ::stack error\n";
    exit(0);
   }

   postfix[++x]=stack[top];
   top–-;

   r=r+rank(postfix[x]);
   
   if(r<1)
   {
    cout<<"Invalid expression  ::r<1\n";
    exit(0);
   }
  }

  if(input_p( next ) != stack_p( stack[top]))
   stack[++top]=next;
  else
   top–-;

  i++;
  next=infix[i];
 }
 postfix[++x]='''';

 if(r!=1 || top!=0)
 {
  cout<<"Invalid expression ::error in rank or stack\n";
  exit(0);
 }

 cout<<"\n\nThe corresponding postfix expression is ::\n";
 cout<<postfix<<endl;
}

int main()
{
 expression obj;
 obj.convert();
 return 0;
}

1> ------构建已开始:项目:infix，配置:Debug Win32 ------
1>正在编译...
1> infix.cpp
1> z:\ math \ arianfar \ mydocs \ Visual Studio 2008 \ projects \ infix \ infix \ infix.cpp(94):错误C2137:空字符常量
1> z:\ math \ arianfar \ mydocs \ Visual Studio 2008 \ projects \ infix \ infix \ infix.cpp(106):错误C2137:空字符常量
1> z:\ math \ arianfar \ mydocs \ visual studio 2008 \ projects \ infix \ infix \ infix.cpp(118):错误C2065:"top–":未声明的标识符
1> z:\ math \ arianfar \ mydocs \ Visual Studio 2008 \ projects \ infix \ infix \ infix.cpp(118):错误C2059:语法错误:'';''
1> z:\ math \ arianfar \ mydocs \ Visual Studio 2008 \ projects \ infix \ infix \ infix.cpp(132):错误C2065:``top–'':未声明的标识符
1> z:\ math \ arianfar \ mydocs \ Visual Studio 2008 \ projects \ infix \ infix \ infix.cpp(132):错误C2059:语法错误:'';''
1> z:\ math \ arianfar \ mydocs \ Visual Studio 2008 \ projects \ infix \ infix \ infix.cpp(137):错误C2137:空字符常量
1>生成日志保存在"file://\\ scidc01 \ bsprof $ \ math \ arianfar \ mydocs \ visual studio 2008 \ projects \ infix \ infix \ Debug \ BuildLog.htm"中.
1>中缀-7个错误，0个警告
========== Build:0成功，1失败，0最新，跳过0 ==========


它是后缀程序的前缀:confused:

1>------ Build started: Project: infix, Configuration: Debug Win32 ------
1>Compiling...
1>infix.cpp
1>z:\math\arianfar\mydocs\visual studio 2008\projects\infix\infix\infix.cpp(94) : error C2137: empty character constant
1>z:\math\arianfar\mydocs\visual studio 2008\projects\infix\infix\infix.cpp(106) : error C2137: empty character constant
1>z:\math\arianfar\mydocs\visual studio 2008\projects\infix\infix\infix.cpp(118) : error C2065: ''top–'' : undeclared identifier
1>z:\math\arianfar\mydocs\visual studio 2008\projects\infix\infix\infix.cpp(118) : error C2059: syntax error : '';''
1>z:\math\arianfar\mydocs\visual studio 2008\projects\infix\infix\infix.cpp(132) : error C2065: ''top–'' : undeclared identifier
1>z:\math\arianfar\mydocs\visual studio 2008\projects\infix\infix\infix.cpp(132) : error C2059: syntax error : '';''
1>z:\math\arianfar\mydocs\visual studio 2008\projects\infix\infix\infix.cpp(137) : error C2137: empty character constant
1>Build log was saved at "file://\\scidc01\bsprof$\math\arianfar\mydocs\visual studio 2008\projects\infix\infix\Debug\BuildLog.htm"
1>infix - 7 error(s), 0 warning(s)
========== Build: 0 succeeded, 1 failed, 0 up-to-date, 0 skipped ==========


it is an infix to postfix program:confused:

推荐答案

\ math \ arianfar \ mydocs \ visual studio 2008 \ projects \ infix \ infix \ Debug \ BuildLog.htm"
1>中缀-7个错误，0个警告
========== Build:0成功，1失败，0最新，跳过0 ==========


它是后缀程序的前缀:confused:

\math\arianfar\mydocs\visual studio 2008\projects\infix\infix\Debug\BuildLog.htm"
1>infix - 7 error(s), 0 warning(s)
========== Build: 0 succeeded, 1 failed, 0 up-to-date, 0 skipped ==========


it is an infix to postfix program:confused:

感谢更新:

Thanks for the update:

z:\math\arianfar\mydocs\visual studio 2008\projects\infix\infix\infix.cpp(94) : error C2137: empty character constant

从infix.cpp(94)中查看infix.cpp的第94行.

Look at line 94 of infix.cpp - from the "infix.cpp(94)"

infix[l+1]='''';

不允许同时使用两个引号字符:它们不是字符.
我怀疑您的意思是"\ 0"作为空终止符.同样适用于第106行.
只是通过列表来查看与该行本身相关的每个错误消息就可以了！

Two quote characters together are not allowed: they are not a character.
I suspect that you mean ''\0'' as a null terminator character instead. The same will apply to line 106.
Just work though the list looking at each error message in relation to the line itself!

对于空字符"常量，我认为''无效.如果要使用空字符，则需要使用''\ 0"或""

在第118/132行上，您最上面的减号之一-不是减号，而是其他字符，导致这些行的两个错误.

For the "empty character" constants, I don''t think '''' is valid. If you want the null character, you need to use ''\0'' or ""

On line 118/132, one of your minus signs in top-- is not a minus sign but some other character, causing both errors for those lines.

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