doubly linkedList

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

struct Task {
  char description[100];
  struct Task* next;
  struct Task* previous;
};

struct Task* createTask(char description[]){
 struct Task* newTask = (struct Task*)malloc(sizeof(struct Task));
 strcpy(newTask->description, description);
 newTask->next = NULL;
 newTask->previous = NULL;
 return newTask;
}

void addTask(struct Task** head, struct Task* newTask){
 if(*head == NULL) {
   *head = newTask;
 } else {
   struct Task* currentElement = *head;
 while(currentElement->next != NULL){
  currentElement = currentElement->next;
  }
 currentElement->next = newTask;
 newTask->previous = currentElement;
 }
}

struct Task* displayFirstTask(struct Task* head){
 if (head == NULL){
   printf("No tasks found!\n");
 } else{
  struct Task* firstTask = head;
  while(firstTask->previous !=NULL){
   firstTask = firstTask-> previous;
  }
  return firstTask;
 }
}

void deleteTask(struct Task** head, struct Task* task){
 if (*head == task){
   *head = task->next;
 }
 if(task->previous !=NULL){
  task->previous->next = task->next;
 }
 if(task->next !=NULL){
  task->next->previous = task->previous;
 }
 free(task);
}
void displayTasks(struct Task* head){
 struct Task* currentTask = head;
 if(currentTask == NULL){
  printf("No tasks found!\n");
 } else{
  printf("Tasks:\n");
  while(currentTask !=NULL){
   printf("%s\n", currentTask->description);
   currentTask = currentTask->next;
  }
 }
}
 void freeAllTasks(struct Task** head){
  struct Task* currentTask = *head;
  while(currentTask !=NULL){
   struct Task* next = currentTask->next;
   free(currentTask);
   currentTask = next;
  }
  *head = NULL;
 }

 int main(){

  //initialize queue
  struct Task* tasks = NULL;

  //initialize tasks
  struct Task* firstTask = createTask("Task 1");
  struct Task* secondTask = createTask("Task 2");
  struct Task* thirdTask = createTask("Task 3");

  //add tasks to queue
  addTask(&tasks,firstTask);
  addTask(&tasks->next, secondTask);
  addTask(&tasks->next, thirdTask);

  // print  all tasks
  displayTasks(tasks);
  //print first element in fifo
  struct Task* firstTaskInQueue = displayFirstTask(tasks);
  if(firstTask !=NULL){
   printf("First Task: %s\n", firstTaskInQueue -> description);
 }
  //delete specific task
  deleteTask(&tasks,firstTask);
  //show result
  displayTasks(tasks);
  //delete all tasks to save memory
  freeAllTasks(&tasks);
  //show result
  displayTasks(tasks);
 }