Implementation of multiple stacks in a single linear array
//Include the necessary header files
#define SIZE 12 //Size of array(Vary as per need)
#define MAX 4 //Maximum number of stacks to store(vary as per need)
typedef struct
{
int stk[SIZE];
int top[MAX];
int boundary[MAX];
}STACK;
void push();
void pop();
void display();
int main()
{
STACK s;
int choice, i, j, n;
s.top[0] = s.boundary[0]=-1;
printf("\nEnter the number of stacks you want to implement: ");
scanf("%d", &n);
for(i=1 ; i < n ; i++)
{
s.top[i] = s.boundary[i] = ((SIZE/n)*i)-1;
}
s.boundary[n] = SIZE-1;
do
{
printf("\n\nOperation on three stacks:");
printf("\n\n1.) Push");
printf("\n2.) Pop");
printf("\n3.) Display");
printf("\n4.) Exit");
printf("\n\nEnter your choice: ");
scanf("%d", &choice);
switch( choice )
{
case 1: printf("\nEnter the stack number in which element is to be pushed(1- %d): ", n);
scanf("%d", &j);
if(j>n || j<1)
break;
push(&s, j);
break;
case 2: printf("\nEnter the stack number to pop element from(1-%d): ", n); scanf("%d", &j);
if(j>n || j<1);
break;
pop(&s, j);
break;
case 3: printf("\nEnter the stack number to display(1-%d): ", n);
scanf("%d", &j);
if(j>n || j<1)
break;
display(s, j);
break;
case 4: break;
default: printf("\nInvalid choice! Enter again.");
}
}while(choice!=4);
getch();
}
void push(STACK *p, int j)
{
int i;
i=j-1;
if(p->top[i] == p->boundary[j])
{
printf("\nStack%d is overflow", j);
}
else
{
(p->top[i])++;
printf("\nEnter the element to push: ");
scanf("%d", &p->stk[p->top[i]]);
}
}
void pop(STACK *p, int j)
{
int i;
i=j-1;
if(p->top[i] == p->boundary[i])
{
printf("\nStack%d is underflow", j);
}
else
{
printf("\nPopped element: %d", p->stk[(p->top[i])--]);
}
}
void display(STACK s, int j)
{
int i, k;
i=j-1;
if(s.top[i] == s.boundary[i])
{
printf("\nStack%d is empty", j);
}
else
{
printf("\nStack%d is: \n", j);
for(k=s.top[i]; k>s.boundary[i]; k--)
{
printf("\n%d", s.stk[k]);
}
}
}
}
