stack all operation

#include <stdio.h>
int size=10;

struct stack 
{
    
 int top;
 int a[10];

};
void push(struct stack *p,int data)
{
    if(p->top==size-1)
    {
        printf("stack is over flow right now");
    }
    else
    {
        p->top++;
        p->a[p->top]=data;
    }
}
void pop(struct stack *p)
{
    if(p->top==-1)
    {
        printf("stack is empty right now");
    }
    else{
        int y=p->top--;
        printf("%d\n",p->a[y]);
    }
}
void peep(struct stack *p,int index)
{
    if(p->top==-1)
    {
        printf("stack is empty right now");
    }
    else
    {
        printf("%d\n",p->a[p->top-index+1]);
    }
}
void display(struct stack *p)
{
    if(p->top==-1)
    {
        printf("stack is empty right now");
    }
    else
    {
        for(int i=p->top;i>=0;i--)
        {
            printf("%d\n",p->a[i]);
        }
    }
    
}

int main()
{
    struct stack s;
    s.top=-1;
    int n;
    int w;
    int e;
    while(1)
    {
        printf("-----------------------------------------------\n");
        printf("enter the number \n 1)push operation \n 2) peep operation \n 3)pop operatin  \n 4) display \n 5) exit \n");
        printf("-----------------------------------------------\n");
        scanf("%d",&n);
        
        switch(n)
        {
            case 1:
            printf("enter the number\n");
            scanf("%d",&w);
            push(&s,w);
            break;
            
            case 2:
            
            printf("enter the index in between 1 to 10\n");
            scanf("%d",&e);
            peep(&s,e);
            break;
            
            case 3:
            pop(&s);
            break;
            
            case 4:
            display(&s);
            break;
            
            case 5:
            exit(0);
           
        }
    }

    return 0;
}