stack

#include<stdio.h>
int a[10000];
int max;
top=0;
int push(int b)
{
    a[top]=b;

}

int pop()
{
    int temp;
    temp=a[top-1];
    a[top-1]=0;
    return temp;
}
void display()
{

    int i;

    printf("\n\n");
    for(i=max-1;i>=0;i--){
        printf("%d\n",a[i]);

    }
    printf("\n\n");
}

int main()
{
    int a,i,n,p;
    printf("Enter the size of stack:");
    scanf("%d",&max);
    for(i=0;;i++){
        printf("Enter 1 for push\nEnter 2 for pop\nEnter 3 for see stack\n");
        scanf("%d",&a);
        if(a==1){
                if(top>=max){
                    printf("stack overflow\nCan't push\n");
                    continue;
                }
            printf("\nEnter the number for push:\n");
            scanf("%d",&n);
            push(n);
            top++;
        }
        else if(a==2){
                if(top==0){
                    printf("stack underflow\nCan't pop\n");
                    continue;
                }
            p=pop();
            printf("\nThe poped item is %d\n",p);
            top--;
        }
        else{
           display();
        }
    }

}