9.c

#include <stdio.h>

#define MAXSIZE 5

 

struct stack

{

    int stk[MAXSIZE];

    int top;

};

typedef struct stack STACK;

STACK s;

 

void push(void);

int  pop(void);

void display(void);

 

void main ()

{

    int choice;

    int option = 1;

    s.top = -1;

 

    printf ("STACK OPERATION\n");

    while (option)

    {

        printf ("------------------------------------------\n");

        printf ("      1    -->    PUSH               \n");

        printf ("      2    -->    POP               \n");

        printf ("      3    -->    DISPLAY               \n");

        printf ("      4    -->    EXIT           \n");

        printf ("------------------------------------------\n");

 

        printf ("Enter your choice\n");

        scanf    ("%d", &choice);

        switch (choice)

        {

        case 1:

            push();

            break;

        case 2:

            pop();

            break;

        case 3:

            display();

            break;

        case 4:

            return;

        }

        fflush (stdin);

        printf ("Do you want to continue(Type 0 or 1)?\n");

        scanf    ("%d", &option);

    }

}

/*  Function to add an element to the stack */

void push ()

{

    int num;

    if (s.top == (MAXSIZE - 1))

    {

        printf ("Stack is Full\n");

        return;

    }

    else

    {

        printf ("Enter the element to be pushed\n");

        scanf ("%d", &num);

        s.top = s.top + 1;

        s.stk[s.top] = num;

    }

    return;

}

/*  Function to delete an element from the stack */

int pop ()

{

    int num;

    if (s.top == - 1)

    {

        printf ("Stack is Empty\n");

        return (s.top);

    }

    else

    {

        num = s.stk[s.top];

        printf ("poped element is = %dn", s.stk[s.top]);

        s.top = s.top - 1;

    }

    return(num);

}

/*  Function to display the status of the stack */

void display ()

{

    int i;

    if (s.top == -1)

    {

        printf ("Stack is empty\n");

        return;

    }

    else

    {

        printf ("\n The status of the stack is \n");

        for (i = s.top; i >= 0; i--)

        {

            printf ("%d\n", s.stk[i]);

        }

    }

    printf ("\n");

}