Push problem in Stack

[Ltp]

#include <iostream>
using namespace std;
class stack{
private:
	int *st;
	int s;
	int top;
public:
	stack(int);
	void set_values();
	void get_values();
	void push(int);
};

stack::stack(int x)
{
	s=x;
	top=0;
	st=new int[s];
}

void stack::set_values()
{
	for(int i=0; i<s; ++i)
		st[i]=rand()%10;
}
void stack::get_values()
{
	for(int i=0; i<s; ++i)
		cout<<st[i]<<endl;
}

void stack::push(int x)
{
	st[++top]=x;
}


int main()
{
	stack sc(10);
	
	sc.set_values();
	sc.get_values();
	sc.push(?);

	system ("Pause");
	return 0;
}

sc.push(?);

What should I put here as argument?

[TheGrayWolf]

The element of the type your stack was designed for. set_values() is kind of meaningless in this context. Your class lacks dtor, copy ctor and assignment operator.

[Ltp]

Ok, I edited the code. But whats wrong now?

#include <iostream>
using namespace std;
class stack{
private:
	int *st;
	int s;
	int top;
public:
	stack(int);
	//void set_values();
	//void get_values();
	void push(int);
};

stack::stack(int x)
{
	s=x;
	top=0;
	st=new int[s];
}
/*
void stack::set_values()
{
	for(int i=0; i<s; ++i)
		st[i]=rand()%10;
}
void stack::get_values()
{
	for(int i=0; i<s; ++i)
		cout<<st[i]<<endl;
}
*/
void stack::push(int x)
{
	st[++top]=x;
}

int main()
{
	stack sc(10);
	
	//sc.set_values();
	//sc.get_values();
	
	for(int i=0; i<s; ++i){
		st[i]==rand()%10;
		sc.push(st[i]);
	}

	system ("Pause");
	return 0;
}

[MrHutch]

void Stack::push( int x )
{
   if( top < s )
      st[top++] = x;
   else
      std::cerr << "Stack overflow!\n";
}

[Ltp]

Variables *st and s are invalid in main(). Is it because I initialized them in "private:"?

[Ltp]

Dude, the problem for me is in main(); not in push()
I need to pass random values in push().

[Ltp]

void stack::set_values()
{
	for(int i=0; i<s; ++i)
		st[i]=rand()%10;
}

In this function, s and st are valid because of initialization in private:.

int main()
{
	stack sc(10);
	
	//sc.set_values();
	//sc.get_values();
	
	for(int i=0; i<s; ++i){
		st[i]==rand()%10;
		sc.push(st[i]);
	}

	system ("Pause");
	return 0;
}

But here, s and st are invalid although I've initialized in private:. Why?

[TheGrayWolf]

You answered you own question. You've declared them private, so they won't be available with direct access outside of the class. For example, in order to retrieve the value of s, you'll need an accessor method for s. Just overload operator[], #include <ctime> and <cstdlib>, generate and assign the numbers to sc.

[coder777]

But here, s and st are invalid although I've initialized in private:. Why?

That has nothing to do with private. s and st are members of stack and can only accessed via sc.


[EDIT]
to fill your stack with value do it like so:

for(int i=0; i<10; ++i){
		sc.push(rand()%10);
	}

[Normally you should call srand() before rand()]

[Ltp]

@TheGrayWolf

overload operator[], #include <ctime>, generate and assign the numbers to sc

Not clear to me.

[TheGrayWolf]

Look at coder777's post. What i described is not neccessary.

P.S. But you still need the destructor, operator= and copy ctor.

[Ltp]

Thanx a lot coder. Part of the code has been solved.