反轉連結串列
題目描述
輸入一個連結串列,反轉連結串列後,輸出新連結串列的表頭。
題目連結: 反轉連結串列
程式碼
/**
* 標題:反轉連結串列
* 題目描述
* 輸入一個連結串列,反轉連結串列後,輸出新連結串列的表頭。
* 題目連結:
* https://www.nowcoder.com/practice/75e878df47f24fdc9dc3e400ec6058ca?tpId=13&&tqId=11168&rp=1&ru=/ta/coding-interviews&qru=/ta/coding-interviews/question-ranking
*/
public class Jz15 {
public ListNode reverseList(ListNode head) {
if (head == null || head.next == null) {
return head;
}
ListNode first = head, second = head.next;
first.next = null;
while (first != null && second != null) {
ListNode temp = first;
first = second;
second = second.next;
first.next = temp;
}
return first;
}
public static void main(String[] args) {
ListNode head = new ListNode(1);
head.next = new ListNode(2);
head.next.next = new ListNode(3);
System.out.println("before reverse");
ListNode cur = head;
while (cur != null) {
System.out.print(cur.val + " ");
cur = cur.next;
}
System.out.println();
Jz15 jz15 = new Jz15();
ListNode result = jz15.reverseList(head);
System.out.println("after reverse");
ListNode cur1 = result;
while (cur1 != null) {
System.out.print(cur1.val + " ");
cur1 = cur1.next;
}
}
}
【每日寄語】 生活的本質就是幸福的活著,而生活的智慧就是活出自己想要的樣子。