Infix to Postfix Conversion

static
char exp[50];

static
int i=0,len,top=1,isp,icp;

static
char x,stack[50];

#include<stdio.h>

void
main()

{

void rec(char c);

static
char yn;

char ch;

clrscr();

stack[1]='#';

top=1;

clrscr();

printf("\n\t\tINFIX
TO POSTFIX CONVERSION");

printf("\n\t\t~~~~~~~~~~~~~~~~~~~~~~~~~~~
");

printf("\n\n\tEnter
the Infix expression (! for End): ");

for(len=1;(exp[len]=getchar())!='\n';len++);

if(exp[len-1]=='!')

{

printf("\n\n\tEqvalent
Postfix Expression => ");

rec(exp[0]);

}

else

printf("\n\n\t\t
You must type ! on end");

getch();

}

void
rec(char x)

{

i++;

if(x=='!')

{

while(top>1)

{

printf("%c",stack[top]);

top--;

}

return;

}

if(((x>=65)&&(x<=90))||((x>=97)&&(x<=122)))

printf("%c",x);

if(x==')')

{

while(stack[top]!='(')

{

printf("%c",stack[top]);

top--;

}

top--;

}

if((x=='^')||(x=='*')||(x=='/')||(x=='+')||(x=='-')||(x=='('))

{

do

{

icp=isp=0;

if((x=='+')||(x=='-'))

icp=1;

if((stack[top]=='+')||(stack[top]=='-'))

isp=1;

if((x=='*')||(x=='/'))

icp=2;

if((stack[top]=='*')||(stack[top]=='/'))

isp=2;

if(x=='(')

icp=4;

if(stack[top]=='(')

isp=0;

if(stack[top]=='^')

isp=3;

if(x=='^')

icp=4;

if(isp>=icp)

{

printf("%c",stack[top]);

top--;

}

if(top==1)

break;

}while(isp>=icp);

top++;

stack[top]=x;

}

while(i<len)

{

rec(exp[i]);

}

}