LapProgram12.c

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

typedef struct node
{
    char name[25];
    struct node *link;
}name;

name *head = NULL;
int count = 0;

void insertName(){
  name *ptr, *cur;
  ptr = (name *)malloc(sizeof(name));
  if(ptr == NULL){
    printf("Memory Allocation Failed");
    return;
  }
  char a[25];
  printf("Enter name to be stored\n");
  scanf("%s", a);
  strcpy(ptr->name, a);

  if(head == NULL){
    head = ptr;
    ptr->link = NULL;
    count++;
  } else {
    cur = head;

     if(strcmp(head->name, ptr->name) > 0){
        ptr->link = head;
        head = ptr;
      }
     else if(strcmp(head->name, ptr->name) == 0){
        ptr->link = head->link;
        head->link = ptr;
     }

     else {
       cur = head;
       for(int i = 0; i < count-1; i++){
        int r = strcmp((cur->link)->name, ptr->name);
        if(r==0){
          name *next;
          next = cur->link;
          ptr->link = next->link;
          next->link = ptr;
          break;
        }
        else if(r>0){
          ptr->link = cur->link;
          cur->link = ptr;
          break;
        }
        else if(r<0){
          cur = cur->link;
          continue;
        }
      }
    }
    count++;
  }
  
}

void deleteName(){
  char a[25]; int i;
  printf("Enter name to be deleted\n");
  scanf("%s", a);
  name *cur;
  cur = head;
  if(strcmp(head->name, a) == 0){
    head = head -> link;
    free(cur);
    count--;
    printf("Found the name %s and deleted \n", a);
  }else {
    for(i =0; i<count-1; i++){
      if(strcmp((cur->link)->name, a) == 0){
        name *tmp;
        tmp = (cur->link);
        cur->link = tmp->link;
        free(tmp);
        count--;
        printf("Found the name %s and deleted \n", a);
        break;
      } else {
        cur = cur-> link;
        continue;
      }
    }
  }

  if(i == count-1)
    printf("The name %s does not exist in the list", a);
}

void displayName(){
  if(head == NULL){
    printf("The Name List is empty, nothing to display\n");
    return;
  }
  name *cur = head;
  while(cur != NULL){
    printf("%s \n", cur->name);
    cur = cur->link;
  }
}

int main()
{
  int c;
  while(1){
    printf("Enter 1 to insert, 2 to delete, 3 to display and 4 to exit\n");
    scanf("%d", &c);
    switch(c){
      case 1:
       insertName();
       break;

      case 2:
        deleteName();
        break;

      case 3:
        displayName();
        break;

      case 4:
        return 0;
      default:
       printf("Invalid input");
    }
  }
 return 0;
}