Java在循环链接列表中搜索元素
在此程序中,我们创建了一个循环链接列表并搜索列表中的节点。
考虑上述示例。假设我们需要搜索节点5。要解决此问题,我们将遍历列表并将每个节点与5进行比较。如果找到匹配项,则将标志设置为true,并打印出节点5的位置。在此示例中,节点5位于位置2。
算法
定义一个代表列表中节点的Node类。它有两个属性数据,下一个将指向下一个节点。
定义另一个用于创建循环链表的类,它具有两个节点: head和tail。
search()将在列表中搜索一个节点: 变量i会跟踪搜索到的节点的位置。 变量标记将存储布尔值false。 当前将指向头节点。 通过将current递增到current.next并将i递增到i + 1来遍历循环。 将每个节点的数据与搜索到的节点进行比较。如果找到匹配项,则将标志设置为true。 如果flag为true,则打印搜索到的节点的位置。 否则,打印消息"列表中不存在元素"。
程序:
public class SearchNode {
//Represents the node of list.
public class Node{
int data;
Node next;
public Node(int data) {
this.data = data;
}
}
//Declaring head and tail pointer as null.
public Node head = null;
public Node tail = null;
//this function will add the new node at the end of the list.
public void add(int data){
//Create new node
Node newNode = new Node(data);
//Checks if the list is empty.
if(head == null) {
//if list is empty, both head and tail would point to new node.
head = newNode;
tail = newNode;
newNode.next = head;
}
else {
//tail will point to new node.
tail.next = newNode;
//New node will become new tail.
tail = newNode;
//Since, it is circular linked list tail will point to head.
tail.next = head;
}
}
//Searches for a node in the list
public void search(int element) {
Node current = head;
int i = 1;
boolean flag = false;
//Checks whether list is empty
if(head == null) {
System.out.println("List is empty");
}
else {
do{
//Compares element to be found with each node present in the list
if(current.data == element) {
flag = true;
break;
}
current = current.next;
i++;
}
while(current != head);
if(flag)
System.out.println("Element is present in the list at the position : " + i);
else
System.out.println("Element is not present in the list");
}
}
public static void main(String[] args) {
SearchNode cl = new SearchNode();
//Adds data to the list
cl.add(1);
cl.add(2);
cl.add(3);
cl.add(4);
//Search for node 2 in the list
cl.search(2);
//Search for node in the list
cl.search(7);
}
}
输出:
Element is present in the list at the position: 2
Element is not present in the list