Simple Linked list

#include

#include

struct node{

        int val;

        struct node *next;        // to store the next value

};

void insert(struct node**);

void delete(struct node**);

void traverse(struct node**);

int main()

{

  struct node *head=NULL;

  int opt=0;

   while(1){

          printf("Select an option \n 1.Insert 2.Delete 3.Exit 4. Traverse\n");

          scanf("%d",&opt);

          switch(opt){

          case 1:{insert(&head); break; }

          case 2:{delete(&head);break;}

          case 3:{ exit(0);break; }

          case 4:{traverse(&head);}

          default:{printf("Invalid no");}

        }

     }

}

void traverse(struct node **head)   // function to traverse

{                                   // input Address of head

    printf("\n");

    struct node *ptr;

    if(*head==NULL){

       printf("List Empty");

        return;

        }

    ptr=*head;

    while(ptr!=NULL){

       printf(" %d",ptr->val);

       ptr=ptr->next;

    }

   printf("\n");

}

void insert(struct node **head)        // function to insert new node

{                                      // input address of head

   struct node *ptr,*temp;

   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);

    temp=*head;

    if(temp==NULL){

      ptr->next=NULL;

      *head=ptr;

       return;

     }

    while(temp->next!=NULL)temp=temp->next;

    temp->next=ptr;

}

void delete(struct node **head)          // function to delete a node

{                                        // input address of head

    struct node *ptr=*head;

    struct node *prevptr=NULL;

    int val;

    if(*head==NULL){

        printf("List empty");

        return;

    }

   printf("Enter the value to delete\n");

   scanf("%d",&val);

    while((ptr->val!=val)&&(ptr->next!=NULL)){

        prevptr=ptr;

        ptr=ptr->next;

    }

     if(ptr->val!=val){

          printf("Value not found\n");

          return;

     }

    if(prevptr==NULL){                  //if selected element has no previous element

        *head=ptr->next;

         free(ptr);

         return;

     }

     prevptr->next=ptr->next;

     traverse(head);

     free(ptr);

}