rpn calculator

[mido elnaggar]

i ve done so far this code but it deals only with 1 digit numbers i dont know how to make it work for 2 or more digited no.s using atoi or atof functions

#include"stdio.h"
#include"stdlib.h"
#include"string.h"
char postfix[100];
int stack[100];
int top=-1;
void push(int x)
{
top++;
stack[top]=x;
}
int pop()
{
return stack[top--];
}
int evalpost()
{
int a,b,i,temp,result,len;
len=strlen(postfix);
for(i=0;i<len;i++)
{
if(postfix[i]<='50'&&postfix[i]>='0')
push(postfix[i]-'0');
else
{
a=pop();
b=pop();
switch(postfix[i])
{
case'+':
temp=a+b;break;
case'-':
temp=b-a;break;
case'*':
temp=a*b;break;
case'/':
temp=b/a;break;
}
push(temp);
}
}
result=pop();
return result;
}
void main()
{
printf("enter rpn\n");
gets(postfix);
top=-1;
int x=evalpost();
printf("%d\n",x);
}




and thanks for ur concern

[whodgson]

Do you mean revs/nautical_mile..........and please put your code in between code tags which makes it much easier to read.
See what you can make of the following:

cout<<"\ndemonstrating the atoi()function\n";
 
    const char* s="  21xy 3";
    const char*s1= " 74.7xyz ";
    cout<<"the first string is \n"<<s<<endl;
    cout<<"the second string is \n"<<s1<<endl;
    n=atoi(s);
    m=atoi(s1);
    cout<<"after converting strings to integers ";
    cout<<"s= "<<n<<" and s1="<<m<<endl;
    cout<<"the product of s and s1 is "<<n*m<<endl; 
 
 
char q;
cout<<"press any key to continue...";
cin.get(q);
return 0;    
 
}    
/*
demonstrating the atoi()function
the first string is
  21xy 3
the second string is
 74.7xyz
after converting strings to integers s= 21 and s1=74
the product of s and s1 is 1554
press any key to continue...*/