#include<stdio.h>
#include<conio.h>
#define MAXSTK 10

struct item
{
    int n;
    char beg;
    char end;
    char aux;
    char add;
};

struct stack
{
    int top;
    struct item data[MAXSTK];
};

void push(struct stack *, struct item);
struct item pop(struct stack *);
void tower(int, char, char, char);
void main()
{
    int n;
    clrscr();
    printf("Enter how many rings");
    scanf("%d",&n);
    tower(n,'A','B','C');
    getch();
}

void push(struct stack *p, struct item it)
{
    if(p->top == MAXSTK-1)
    {
        printf("Stack is full");
        return;
    }
    p->top++;
    p->data[p->top] = it;
}

struct item pop(struct stack *p)
{
    struct item it;
        if(p->top == -1)
        {
            printf("Stack is empty");
            return it;
        }
        it = p->data[p->top];
        p->top--;
        return(it);
}

void tower(int n, char beg, char aux, char end)
{
    struct stack s1;
    struct item currentitem;
    int t;
    s1.top = -1;
    step1:
        if(n==1)
        {
            printf("\n Disk No 1 is transferred from %c to %c",beg,end)
            goto step5;
        }
    step2:
        currentitem.n = n;
        currentitem.beg = beg;
        currentitem.end = end;
        currentitem.aux = aux;
        currentitem.add = 3;
        push(&s1,currentitem);
        n--;
        t = end;
        end = aux;
        aux = t;
        goto step1;
    step3:
        printf("\n Disk no %d is transferred from %c to %c",n,beg,end);
    step4:
        currentitem.n = n;
        currentitem.beg = beg;
        currentitem.end = end;
        currentitem.aux = aux;
        currentitem.add = 5;
        push(&s1, currentitem);
        n--;
        t = aux;
        aux = beg;
        beg = t;
        goto step 1;
    step5:
        if(s1.top == -1)
            return;
        currentitem = pop(&s1);
        n = currentitem.n;
        beg = currentitem.beg;
        end = currentitem.end;
        aux = currentitem.aux;

        switch(currentitem.add)
        {
            case 3:
                goto step3;
            case 5:
                goto step5;
        }
}