conversion of infix to postfix and its evaluation

[Abiha]

i didn't understand ur answer plz reply in more modified way and also tell wats the prob in a=pop(); & in b=pop();
and also tell the output of
a+b*c/d^e rply as quick as possible thankyou

#include<iostream.h>
#include<conio.h>
#include<string.h>
#include<stdio.h>
#include<ctype.h>
#include<math.h>
#define MAX 20
char stack[MAX];
int top=-1;
char pop();
void push(int val);


int prcd(char symbol)
{
switch(symbol)
{
case '+':
case '-':
return 2;
case '*':
case '/':
return 4;
case '^':
case '$':
return 6;
case '(':
case ')':
case '#':
return 1;
}
}


int isoperator(char symbol)
{
switch(symbol)
{
case '+':
case '-':
case '*':
case '/':
case '^':
case '$':
case '(':
case ')':
return 1;
default:
return 0;
}
}

void convertip(char infix[],char postfix[])
{
int i,j=0;
char symbol;
stack[++top]='#';

for(i=0;i<strlen(infix);i++)
{
symbol=infix[i];
if(isoperator(symbol)==0)
{
postfix[j]=symbol;
j++;
}
else
{
if(symbol=='(')
push(symbol);
else if(symbol==')')
{
while(stack[top]!='(')
{
postfix[j]=pop();
j++;
}
pop();
}
else
{
if(prcd(symbol)>prcd(stack[top]))
push(symbol);
else
{
while(prcd(symbol)<=prcd(stack[top]))
{
postfix[j]=pop();
j++;
}
push(symbol);
}//end of else
} //end of else
}//end of else
}//end of for
while(stack[top]!='#')
{
postfix[j]=pop();
j++;
}
postfix[j]='\0'; //null terminate string
}//end of function

void main()
{
char infix[20],postfix[20];
clrscr();
cout<<endl<<"Enter the valid infix string:";
gets(infix);
convertip(infix,postfix);
cout<<endl<<"The corresponding postfix string is:";
puts(postfix);
int i=0;
int a,b,c;
while(postfix[i]!='\0')
{
if(isdigit(postfix[i])||isalpha(postfix[i]))
push(postfix[i]-48);
else if(postfix[i]!=32)
{
a=pop();
b=pop();
if(postfix[i]=='*')
c=b*a;
else if(postfix[i]=='/')
c=b/a;
else if(postfix[i]=='+')
c=b+a;
else if(postfix[i]=='^')
c=pow(b,a);
else
c=b-a;
push(c);
}
i++;
}
cout<<endl<<c;

getch();
}

void push(int val)
{
stack[++top]=val;
}
char pop()
{
return stack[top--];
}

Re: conversion of infix to postfix and its evaluation
Hey
Check the prototype for pow...

http://www.cplusplus.com/reference/clibrary/cmath/pow/

and recheck this too..

a=pop();
b=pop();

int<-char ??

[NP-complete]

What the hell is this?? Are u joking with us?? Or is it that you are as stupid as it seems...!!!

[NP-complete]

Okay i see....it seems that you have previously posted this in another thread and now without any reference you have started this thread. So how on earth do you think we will know??

And one more thing, don't you see the watermark in the "post reply" message box regarding CODE TAGS??

Before posting get the know the basic rules at least, believe me there aren't many....

good luck.