o(1)時間刪除單鏈表的某個節點

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

struct Node{
	int m_value;
	Node *m_nextNode;
};
void deleteNode(Node** pHead,Node* toBedelNode){
	if(*pHead==NULL||pHead == NULL||toBedelNode==NULL) return ;
	//判斷是不是末尾節點,是的話從頭再來，不是的話做下替換 
	 if(toBedelNode->m_nextNode!=NULL){
	 	Node *tmp = toBedelNode->m_nextNode;//臨時指針指向後面的節點 
	 	toBedelNode->m_value = tmp->m_value;//交換
		toBedelNode->m_nextNode = tmp->m_nextNode;//在把指針指向後面的後面的節點
		free(tmp);
		tmp = NULL; 
	 }else if(*pHead == toBedelNode){
	 	 //如果就一個節點
		 free(toBedelNode);
		 free(pHead);
		 *pHead = NULL;
		 toBedelNode = NULL; 
	 }else{
	 	//從頭遍歷
		Node *tmp = *pHead;
		while(tmp->m_nextNode!=toBedelNode){
			tmp= tmp->m_nextNode;
		}
	  	free(tmp->m_nextNode);
	  	free(toBedelNode);
	  	toBedelNode = NULL;
		tmp->m_nextNode = NULL; 
	 }
}