C로 LinkedList 구현 +_+// (아 힘들었어;; ㅋㅋ)

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

typedef struct Node {
 int data;
 struct Node *next;
} node;

typedef struct LinkedList {
 int length;
 struct Node *fNode;
}linkedList;

node* firstNode;

int length;

void initList(struct LinkedList*);
node* getNodeAt(struct LinkedList*, int);
void add(struct LinkedList*, int);
void addInIndex(struct LinkedList*, int , int);
void erase(struct LinkedList*, int);
void replace(struct LinkedList*, int, int);
void reset(struct LinkedList*);
void display(struct LinkedList*);
int get(struct LinkedList*, int);
int isFull(struct LinkedList*);
int isEmpty(struct LinkedList*);
int checkPosition(struct LinkedList*, int);

void initList(struct LinkedList* list){
 if(!isEmpty(list))
  reset(list);
 list->length = 0;
 list->fNode = (node *)malloc(sizeof(node));
}

node* getNodeAt(struct LinkedList* list, int index){
 int i;
 node* current = list->fNode;
 for(i = 0 ; i < index ; i++)
 {
  current = current->next;
 }
 return current;
}

void add(struct LinkedList* list, int entryData){
 node* newNode = (node* )malloc(sizeof(node));
 newNode->data = entryData;
 if(list->length == 0){
  list->fNode = newNode;
 }
 else {
  getNodeAt(list, list->length - 1)->next = newNode;
 }
 list->length +=1;
}

void addInIndex(struct LinkedList* list, int entryData, int position){
 node* oldNode;
 node* newNode = (node* )malloc(sizeof(node));
 newNode->data = entryData;
 if(checkPosition(list, position)) {
  if (position == list->length)
   add(list, entryData);
  else {
   oldNode = getNodeAt(list, position);
   getNodeAt(list, position - 1)->next = newNode;
   newNode->next = oldNode;
  }
  list->length += 1;
 }
}

void erase(struct LinkedList* list, int position){
 node* tempNode = getNodeAt(list, position);
 if(checkPosition(list, position)) {
  if(position == 0){
   tempNode = tempNode->next;
   free(list->fNode);
   list->fNode = tempNode;
  }
  else if(position != 0 && position == list->length){
   getNodeAt(list, position - 1)->next = NULL;
   free(tempNode);
  }
  else {
   getNodeAt(list, position - 1)->next = getNodeAt(list, position + 1);
   free(tempNode);
  }
  list->length -= 1;
 }
}
 
void replace(struct LinkedList* list, int changedData, int position){
 if(checkPosition(list, position))
  getNodeAt(list, position)->data = changedData;
}

void display(struct LinkedList* list){
 if(!isEmpty(list)){
  int i;
  for(i = 0 ; i < list->length; i++) {
   printf("[ %d ] ", getNodeAt(list, i)->data);
  }
 }
 printf("\n");
}
void reset(struct LinkedList* list){
 int i;
 for(i = list->length - 1 ; i >= 0; i--) {
  free(getNodeAt(list, i));
 }
}
int get(struct LinkedList* list, int position){
 if(checkPosition(list, position))
  return getNodeAt(list, position)->data;
 else
  return 0;
}
int isEmpty(struct LinkedList* list){
 return list->length == 0;
}
int checkPosition(struct LinkedList* list, int position){
 return position >= 0 && position < list->length;
}

void main(void){
 linkedList* p_listOne;
 linkedList* p_listTwo;
 p_listOne = (linkedList*) malloc(sizeof(linkedList));
 p_listTwo = (linkedList*) malloc(sizeof(linkedList));

 initList(p_listOne);
 initList(p_listTwo);
 
 add(p_listOne, 100);
 add(p_listTwo, 200);
 add(p_listOne, 100);
 add(p_listTwo, 200);
 add(p_listOne, 100);
 add(p_listTwo, 200);
 add(p_listOne, 100);
 add(p_listTwo, 200);

 display(p_listOne);
 display(p_listTwo);
}

아주~~ 재미있었습니다. free() 라는 함수의 중요성도 깨달았고 -_- ㅋㅋㅋㅋ 포인터의 개념도 더 확실해 졌고.. 잇힝.. 아무튼 너무 재미있어효 ^^ ㅋㅋ