CareerCup

I was asked the same questions and what I did was to declare 2 variables and print out the address of both and compare as done by Neo, but the interviewer said that there were some times when this approach would not be correct and so I wrote another method which he approved, I declared a variable and assigned a pointer which would hold the address of it, in the next line would call a function and pass that pointer value to it, declare a variable there and compare the address of the new variable and the passed value and thus come to know whether the stack is growing upwards or downwards....

please comment on the solution...

Can you elaborate on that?

template<typename T>
bool isGrowingUp(stack<T>& s) {
    T tmp;
    s.push(tmp);
    T *ptr = &s.top();
    s.push(tmp);
    bool up = (++ptr == &s.top());
    s.pop();
    s.pop();
    return up;
}

int a,b;
if(&a>&b)
cout<<"downward";
else
cout<<"upward";

How is this any different than the previous solution? - If the compiler decides to store all local variables in registers and not use the stack at all.

to Nishit,

Why don't you turn your idea into code rather than text....

@Nishit, is the following correct then ?

#include <stdio.h>
#include <stdlib.h>

void stackFn(int *var1)
{
  int var2;
  
  printf("\n Address of first var  = %u ", var1);
  printf("\n Address of second var = %u ", &var2);

  if(var1 > &var2)
    printf("\n Stack is growing downwards.\n");

  else
    printf("\n Stack is growing upwards.\n");
  
} 

void main()
{
  int var1;

  stackFn(&var1);  

}

stack<int> T;
bool isStackGrowing()
{
static int *ptr = NULL;
if(ptr == NULL)
{
if(T.size() > 0)
{
ptr = &T.top();
return true;
}
else
return false;
}
bool b = ptr < &T.top();
ptr = &T.top();
return (b);

}

T.push(20);
T.push(21);


cout<<"isStackGrowing: "<<isStackGrowing()<<endl;
T.pop();
cout<<"isStackGrowing: "<<isStackGrowing()<<endl;

Stack space means not to check the addresses of stuff inside a local stack data structure. Stack space means the space used for a function call. Comparing pointers will work and is a good method.

bravo Brahmananda Reddy ...u shud apply to google..they will surely accept u

Stupid question. Even more stupid answers.

Keyword:
Print the address of a local variable
Recursion

void foo(char *a);

main()
{
char str=' ';
char *a=&str;
foo(a);
}

void foo(char *a)
{
char str=' ';
char *b=&str;
if(a>b)
printf("down");
else
printf("grow");
}