我正在學習循環鏈表。撥打deleteNodeByKey()
刪除頭節點時,我會遇到問題。它適用於其餘節點的刪除。爲什麼如果刪除節點是頭不工作?圓形鏈表:如何糾正我的刪除節點功能?
#include <iostream>
#include <stdlib.h>
using namespace std;
/* structure for a node */
struct node
{
int data;
struct node *next;
};
/* Function to insert a node at the begining of a Circular
linked list */
void push(struct node **head_ref, int data)
{
struct node *ptr = (struct node*)malloc(sizeof(struct node));
ptr->data = data;
ptr->next = *head_ref;
struct node *temp = *head_ref;
/* If linked list is not NULL then set the next of last node.
It is going to last node by circling 1 times.
*/
if(*head_ref != NULL){
while(temp->next != *head_ref){
temp = temp->next;
}
//set last node by ptr
temp->next = ptr;
}
else{
// 1 node circular linked list
ptr->next = ptr;
}
// after push ptr is the new node
*head_ref = ptr;
}
//get the previous node
struct node* getPreviousNode(struct node* current_node){
struct node* prev = current_node;
while(prev->next != NULL && prev->next->data != current_node->data){
prev = prev->next;
}
return prev;
}
/* Given a reference (pointer to pointer) to the head of a list
and a key, deletes the first occurrence of key in linked list */
void deleteNodeByKey(struct node **head_ref, int key)
{
// Store head node
struct node* current_node = *head_ref, *prev;
while(current_node != NULL && current_node->data != key){
current_node = current_node->next;
}
if(current_node == NULL){
return;
}
//Removing the node
if(current_node->data == key){
prev = getPreviousNode(current_node);
prev->next = current_node->next;
current_node->next = NULL;
free(current_node);
return;
}
}
/* Function to print nodes in a given Circular linked list */
void printList(struct node *head)
{
struct node *temp = head;
if(head != NULL){
/*
do-while because at 1st temp points head
and after 1 rotation temp wil come back to head again
*/
do{
cout<<temp->data<<' ';
temp = temp->next;
}
while(temp != head);
cout<<endl;
}
}
int main() {
/* Initialize lists as empty */
struct node *head = NULL;
/* Created linked list will be 11->2->56->12 */
push(&head, 12);
push(&head, 56);
push(&head, 2);
push(&head, 11);
cout<<"Contents of Circular Linked List"<<endl;
printList(head);
deleteNodeByKey(&head, 11);
printList(head);
return 0;
}
下面是代碼鏈接:Source Code
你面臨什麼問題? – molbdnilo
尋求調試幫助的問題(**爲什麼不是這個代碼工作?**)必須包含所需的行爲,特定的問題或錯誤,以及在問題本身**中重現**所需的最短代碼。沒有**明確問題陳述**的問題對其他讀者沒有用處。請參閱:[如何創建最小,完整和可驗證示例](http://stackoverflow.com/help/mcve)。 – Biffen
@ user5005768標籤說C++,但代碼看起來像C.您可能想糾正一個或另一個。 – Biffen