技術標籤：java語法單鏈表連結串列java

通過遍歷，找到連結串列中的第N個結點

程式碼示例：

class Node {
    public int val;
    public Node next;

    public Node(int val) {
        this.val = val;
    }
}
public  class MyLinkedList {

    public Node head;//普通引用，目的是讓head一直指向當前列表的頭

    public void createLinked() {
        this.head = new
 
 Node(12);
        Node node2 = new Node(22);
        Node node3 = new Node(32);
        Node node4 = new Node(42);
        head.next = node2;
        node2.next = node3;
        node3.next = node4;
    }

    public void display() {//列印一個連結串列
        Node cur = this.head;
        while (cur != null) {
 

            System.out.print (cur.val +" ");
            cur = cur.next;
        }
        System.out.println();
    }
    public  Node findN(int n) {
        if (this.head == null){
            System.out.println("連結串列為空");
            return null;
        }
        if (n <=
 
 0){
            System.out.println("n的值不合理");
            return null;
        }
        if (n >size()){
            System.out.println("n太大了");
            return  null;
        }
        Node cur = this.head;
         int count =1;
            while (count != n ) {
            cur = cur.next;
            count ++;
        }
        return cur;
    }
    //得到單鏈表的長度
    public int size(){
        Node cur = this.head;
        int count =0;
        while (cur != null ) {
            cur = cur.next;
            count++;
        }
        return count;
    }
    public static void main(String[] args) {
        MyLinkedList myLinkedList = new MyLinkedList();
        myLinkedList.createLinked();
        myLinkedList.display();
        System.out.println("===================");
        int n=4;
        Node ret = myLinkedList.findN(n);
        System.out.println("第" +n+ "個結點是" + ret.val);
    }

結果：

總結：

1.由於while迴圈中是count和n比較，所以count要從1開始。
2.要把①連結串列是否為空，②n值是否合理，③n是否大於連結串列長度 這三種因素考慮進去。