//反转一个单链表。 -----迭代
//
// 示例:
//
// 输入: 1->2->3->4->5->NULL
//输出: 5->4->3->2->1->NULL
//
// 进阶:
//你可以迭代或递归地反转链表。你能否用两种方法解决这道题?
// Related Topics 链表
package leetcode.editor.cn;
import com.example.demo.ArrayConvertLinkedList;
import com.example.demo.ListNode;
import java.util.Stack;
//Java:反转链表
public class P206ReverseLinkedList {
public static void main(String[] args) {
Solution solution = new P206ReverseLinkedList().new Solution();
// TO TEST
int[] array = {1, 2, 3, 4, 5};
ListNode head = ArrayConvertLinkedList.arrayToNode(array);
head = solution.reverseList(head);
ArrayConvertLinkedList.printNode(head);
}
//leetcode submit region begin(Prohibit modification and deletion)
/**
* Definition for singly-linked list.
* public class ListNode {
* int val;
* ListNode next;
* ListNode(int x) { val = x; }
* }
*/
class Solution {
public ListNode reverseList(ListNode head) {
ListNode prev = null;
ListNode curr = head;
while (curr != null) {
ListNode nextTemp = curr.next;
curr.next = prev;
prev = curr;
curr = nextTemp;
}
return prev;
}
}
//leetcode submit region end(Prohibit modification and deletion)
}