Stack[last in first out]

stack.c

#include<stdio.h>
void push(int x);
int pop(void);
int y;
int stack[2];
int top=0;
int count=0;
int main()
{
    int input,i;
    while(1)
    {
	printf("Press:\n1 for Push to stack\t2 for Pop to stack\n3 for print array \t4 for Exit.\n");
	scanf("%d",&input);
	if(input==1)
	{
	    printf("Enter value for push to stack.\n");
	    scanf("%d",&y);
	    push(y);
	}
	else if(input==2)
	{
	    pop();
	}
	else if(input==3)
	{
	    for(i=count-1;i>=0;i--)
            {
                printf("%d\n",stack[i]);
            }
        if(count==0)
        {
            printf("Stack is empty\n");
        }
        }
        else
        {
            return(0);
        }
    }

    return(0);
}
void push(int x)
{
    if(top==3)
    {
        printf("Stack is over flow.\n");
        top--;

    }
    stack[top] = x;
    top++;
    count++;

    }
int pop(void)
{
    if(stack[top-1]==0)
    {
        printf("Stack is underflow.\n");
        top++;
        count += 1;
    }
    y = stack[top-1];
    top--;
    count--;

    return y;
}