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);

}