Linked List

#include<stdio.h>
#include<stdlib.h>

struct node
{
              int data;
              struct node *next;
};
struct node *root=NULL;



int main()
{
int choice;
while(1)
 {
               printf("Single list operation\n");
               printf("0: Create your list\n");
               printf("1: Display your list data\n");
               printf("2: Delete minimum value in your list\n");
               printf("3: Quit\n");
               printf("Enter your choice:");
               scanf("%d",&choice);
               printf("\n");
               switch (choice)
               {
                    case 0: createList();
                            break;
                    case 1: displayList();
                            break;
                    case 2:
                            printf("List before deleting: ");
                            displayList();
                            deleteMin();
                             printf("List after deleting: ");
                            displayList();
                            break;
                    case 3: exit(1);
                    default: printf("Invalid choice");
               }
 }
              return 0;
}






//FUNCTION TO CREATE A LINKED LIST
void createList()
{
        struct node *temp;
        temp=(struct node*) malloc(sizeof(struct node));
        int num;
        printf("Enter your data:");
        scanf("%d", &num);
        printf("\n");
        temp->data=num;
        temp->next=NULL;
        if (root==NULL)
        {
                      root=temp;
        }
        else
        {
                      struct node *p;
                      p=root;
                      while (p->next !=NULL)
                      {
                                    p=p->next;
                      }
                      p->next=temp;
        }
}

//FUNCTION TO DISPLAY LINKED LIST
void displayList()
{
                            struct node *p;
                            p=(struct node*) malloc(sizeof(struct node));
                            p=root;
    if(p==NULL)
    {
                  printf("List is empty");
    }
else
    {
     while (p!=NULL)
              {
                  printf("%d-->", p->data);
                  p=p->next;
               }
    }
    printf("\n\n");
    return 0;
}


//FUNCTION TO DELETE THE MINIMUM IN YOUR LIST
int deleteMin()
{
     //find min value in the list
     int min;
     struct node *p;
     p=root;
     if (p==NULL)
     {
                   printf("List is empty\n");
                   exit(1);
     }
     else
     {
                   min=p->data;
                   while (p!=NULL)
                   {
                                 if (p->data<min)
                                 {
                                               min=p->data;
                                 }
                    p=p->next;
                   }
     }
      printf("Min value is: %d\n", min);
      struct node *index,*prev;
      index=root;
      while (index!=NULL)
      {
                    if (index->data==min)
                    {
                        if (index==root)
                        {
                                      root=index->next;
                                      free(index);
                                      return 1;
                        }
                       else
                       {
                                     prev->next=index->next;
                                     free(index);
                                     return 1;
                       }
                     }
                   else
                     {
                                   prev=index;
                                   index=index->next;
                     }
      }
return 0;
}