[mister1337]

// inFix to post fix converter

//This does it correctly but, the User must type in the statement but they are given what to type.

#include<iostream>
#include<stdio.h>
#include<conio.h>
#include<vector>
#include<string>
#include <stdlib.h>
#include <stdio.h>
#include<stdlib.h>
#include<fstream>



const int size =50;
char postfix[size],stack[size];
int top=-1;

int precedence(char ch);   //  get the precedence of the operator
char pop();  // pop an element from the stack
char topelement();  // returns the top element of the stack
void push(char ch);  // pushes an element into the stack

using namespace std;

int main()
{
   
//string getdata;
	//int cont=0;
	//fstream data;
   // data.open("C:\\InFix.txt",ios::in);
 //while(!data.eof()){
		//data.getline(getdata,sizeof(data));
	  //  cout<<getdata<<endl;
	//}
  //  system("pause");


   ifstream inFile("C:\\InFix.txt");
   ifstream ftext;
   string word;
   
  
 // cout << getdata; //THis is EMPTY!
	 cout << "Please type The following statement";
	 cout << "\n";
	 
	   
			  cout << "\n";
			 cout << "THis will convert what is in InFix.txt to Post Fix";
			 cout << "\n";
	
	
	
	 char ele,elem,st[2];
	 int prep,pre,popped,j=0,chk=0;
	 strcpy(postfix," ");
	char dirt[size] = "lol"; 
	

 cout << dirt;
//Gets the inFIx typed but this is acutally getting written to the textfile not what you wrote.

	//gets(infix);
	
   
	char infix[size] = "X = A + B"; // this is where the contents of the text file needs to go.
   
	 for(int i=0;infix[i]!=0;i++)
		  {
		  if(infix[i]!='('&&infix[i]!=')'&&infix[i]!='^'&&infix[i]!='*'&&infix[i]!='/'&&infix[i]!='+'&&infix[i]!='-')	 
				postfix[j++]=infix[i];
			  else if(infix[i]=='(')
				 {
						 elem=infix[i];
						 push(elem);
					  }
				  else if(infix[i]==')')
					  {
						 while((popped=pop()) != '(')
							 postfix[j++]=popped;
					  }
				  else
					  {
						 elem=infix[i];
						 //stores precedence of operator from infix
						 pre=precedence(elem);
						 ele=topelement();
						 //stores precedence of operator at top stack
						 prep=precedence(ele);
						
						 if(pre > prep)
						   push(elem);										 
						   
						 else
						   {
	while(prep >= pre)
								  {
					   if(ele=='#')
						   break;
				 popped=pop();
				 ele=topelement();
				 postfix[j++]=popped;
				 prep=precedence(ele);
								   }
			 push(elem);
							}
						 }
			 } 
			 
		  while((popped=pop())!='#')
		 postfix[j++]=popped;
		  postfix[j]='\0';
		  
		  
		 cout<<"\n post fix  Version :"<<postfix<<endl;
	  
		  //was able to write to a file but, only overwrote the exisiting file
	  
		   inFile.close();

		   system("pause");
		   return 0;
}

int precedence(char ch)
{
	   switch(ch)
		  {
			   case '^' : return 5;
			   case '/' : return 4;
			   case '*' : return 4;											
			   case '+' : return 3;
			   case '-' : return 3;
			   case '=' : return 2;			  
			   default  : return 0;
		  }
		  
}

char pop()	  
//pop the element from the stack			
{
	 char ret;
	 if(top!=-1)
	   {  ret =stack[top];
		  top--;
		  return ret;
	   }
	 else
		return '#';
}
						 
char topelement()		
 // return top element from the stack without popping 
{	 
	  char ch;
	  if(top!=-1)
		ch=stack[top];
	  else
		 ch='#';
	   return ch;
}

void push(char ch)		 
 // push an element in the stack
{
	 if(top!=size-1)
		 {
			top++;
			stack[top]= ch;
		 }
}		 
								

This post has been edited by mister1337: 23 September 2009 - 08:27 AM

[NickDMax]

Quote

#include<iostream>
#include<stdio.h>
#include<conio.h>
#include<vector>
#include<string>
#include <stdlib.h>
#include <stdio.h>
#include<stdlib.h>
#include<fstream>

LOL -- covering all your bases eh?

What is the question, what are you having problems with?

Are you receiving any errors? Does this code not work that way you intended it? When asking for help there are a couple items that are vital in order for someone to properly help you:

• Post the code you're having problems with
  
• Post the exact error you're receiving, if you are receiving one
  
• If no error explain what the code is doing versus what you want it to do
  
• Post your question in the body of your post, not the description field

[Crunch]

Read from file using a loop

  string line;
 ifstream myfile ("C:\\example.txt");
 while (! myfile.eof() )
	{
	  getline (myfile,line); 
// copy the contents of line to a array 

}

[mister1337]

But, the contents are not accessable outside of the loop.

[Crunch]

yeah so that's why you need to copy the contents of the line string to a array within the loop

[mister1337]

Almost got it, still an error

	string line;
	char arrays[size]; //here is the array
ifstream myfile ("C:\\InFix.txt");
while (! myfile.eof() )
	{
	  getline (myfile,line); 
// copy the contents of line to a array 

   strncpy(arrays, line, sizeof(arrays)-1);  //not sure of the error


}

[Crunch]

mister1337, on 23 Sep, 2009 - 08:23 AM, said:

   strncpy(arrays, line, sizeof(arrays)-1);  //not sure of the error

strcpy( arrays , line, a) ;

where a == Maximum number of characters to be copied from source.

[mister1337]

Still getting a problem.

  string line;
	int a = 50;// like this?
	char arrays[size]; //here is the array
ifstream myfile ("C:\\InFix.txt");
while (! myfile.eof() )
	{
	  getline (myfile,line); 
// copy the contents of line to a array 

   strcpy(arrays, line, a);  //Hmmmm?


}

[Crunch]

the strcpy definition

char * strncpy ( char * destination, const char * source, size_t num );




both source and destination should be char arrays

you can do this to manually copy the characters to a array

   int pos=0;
   string line;
  char c1[1000];

	while (! myfile.eof() )
	{
	  getline (myfile,line);   
int i =0;
char c=' ';

for(; c!='\0'; i++){
	 c=line[i];
	
   if( c== '\0' )   c1[pos] =  ' ';
   else c1[pos] = c;
	 printf("%c" , c1[pos]);
	  pos++;	  
	  }   
	  }

this will solve your problem

[mister1337]

Thanks Snowflakes, that is helping

 string line;
	int a = 50;// like this?
	char arrays[size]; //here is the array
ifstream myfile ("C:\\InFix.txt");
while (! myfile.eof() )
	{
	  getline (myfile,line); 
// copy the contents of line to a array 


   char * strncpy ( char * arrays, const char * line, size_t a );// this works!


}

cout << arrays[size]; // THis comes out as Jibberish

[poncho4all]

YOu need a for to display an array

for(int i=0; i<size;i++){
cout<<arrays[size];
}

Hope that helps

[mister1337]

All I'm getting is more jibberish even with the count.
The really has to be a way that I can import this

  string line;
	int a = 50;// like this?
	char arrays[size]; //here is the array
ifstream myfile ("C:\\InFix.txt");
while (! myfile.eof() )
	{
	  getline (myfile,line); 
// copy the contents of line to a array 


   char * strncpy ( char * arrays, const char * line, size_t a );// this works!


}

import it then use it

  char infix[size] = "X = A + B"; // I would use arrays inplace of infix
   
	 for(int i=0;infix[i]!=0;i++)
		  {
		  if(infix[i]!='('&&infix[i]!=')'&&infix[i]!='^'&&infix[i]!='*'&&infix[i]!='/'&&infix[i]!='+'&&infix[i]!='-')	 
				postfix[j++]=infix[i];
			  else if(infix[i]=='(')
				 {
						 elem=infix[i];
						 push(elem);
					  }
				  else if(infix[i]==')')
					  {
						 while((popped=pop()) != '(')
							 postfix[j++]=popped;
					  }
				  else
					  {
						 elem=infix[i];
						 //stores precedence of operator from infix
						 pre=precedence(elem);
						 ele=topelement();
						 //stores precedence of operator at top stack
						 prep=precedence(ele);
						
						 if(pre > prep)
						   push(elem);										 
						   
						 else

here.

[poncho4all]

Can you post the txt your trying to read?

[mister1337]

Here it is

Attached File(s)

•  InFix.txt (9bytes)
  Number of downloads: 53

[poncho4all]

Well this is working i copied your text and it worked gets the X = A + B into the array op
Try moving your text into the folder where your .cpp is.

/* This program will read one line from a text file and save it into a string*/

#include <iostream>
#include <fstream>
#include <string>

using namespace std;

int main(){
	char op[20];
	ifstream data ("InFix.txt");
	data.getline(op,sizeof(data));
		cout<<op;
	return 0;
}