Wrong Advices •Discussions Redifined

[Manishalexin]

// This to implement the infix expression to the postfix form
using the data structure stack


#include <stdio.h>
#include <conio.h>
#include <string.h>
#include <ctype.h>
char stack[100];
int top=0;
char exp[100];
struct table
{
char s[2];
int isp;
int icp;
}pr[7];
int isp(char c)
{
int i;
for(i=0;i<=6;i++)
if(pr[i].s[0]==c)
return(pr[i].isp);
return 0;
}
int icp(char c)
{
int i;
for(i=0;i<=6;i++)
if(pr[i].s[0]==c)
return(pr[i].icp);
return 0;
}
void main()
{
int i;
clrscr();
strcpy(pr[0].s,"^");
pr[0].isp=3;
pr[0].icp=4;

strcpy(pr[1].s,"*");
pr[1].isp=2;
pr[1].icp=2;

strcpy(pr[2].s,"/");
pr[2].isp=2;
pr[2].icp=2;

strcpy(pr[3].s,"+");
pr[3].isp=1;
pr[3].icp=1;

strcpy(pr[4].s,"-");
pr[4].isp=1;
pr[4].icp=1;

strcpy(pr[5].s,"(");
pr[5].isp=0;
pr[5].icp=4;

strcpy(pr[6].s,"=");
pr[6].isp=-1;
pr[6].icp=0;

clrscr();
stack[top]='=';
printf("enter the infix expression
");
gets(exp);
i=0;
printf("the postfix expression is
")
while(i<strlen(exp))
{
if(isalpha(exp[i])==0)
{

if(exp[i]==')')
{
while(stack[top]!='(')
{
printf("%c",stack[top]);
top--;
}
top--;
}
else
{
while(isp(stack[top])>=icp(exp[i]))
{
printf("%c",stack[top]);
top--;
}
top++;
stack[top]=exp[i];
}
}
else
printf("%c",exp[i]);
i++;
}
while(top>0)
{
printf("%c",stack[top]);
top--;
}
getch();
}


// End of Project