Simple Linked Stack

#include
#include
struct node{
int val;
struct node *next;
};

void push(struct node**);
void pop(struct node**);

int main()
{
struct node *head=NULL;
int opt=0;

while(1){
printf("Select an option \n 1.Push 2.Pop 3.Exit\n");
scanf("%d",&opt);
switch(opt){
case 1:{push(&head); break; }
case 2:{pop(&head);break;}
case 3:{ exit(0); }
}
}
}
void push(struct node **head) //to insert at begining
{ //input is address of head
struct node *ptr;

ptr=(struct node*)malloc(sizeof(struct node));
if(ptr==NULL){
printf("Allocation failed\n");
return;
}
printf("Enter an integer value\n");
scanf("%d",&ptr->val);
ptr->next=*head;
*head=ptr;

}


void pop(struct node **head) //to pop an element out
{ //input is address of head if(*head==NULL){
printf("\n Stack Empty\n");
return;
}
struct node *ptr;
ptr=*head;
printf("the poped value is%d\n",ptr->val);
*head=ptr->next;
free(ptr);
}