原题链接:https://leetcode.com/problems/merge-two-sorted-lists/description/
这道题目是合并两个有序的单链表。。。尼玛,这不就是《数据结构(C语言版)》上的原题嘛,并不是考察什么高超的算法,就是普通的链表操作知识而已!
import java.util.Stack;
/**
* Created by clearbug on 2018/2/26.
*/
public class Solution {
static class ListNode {
int val;
ListNode next;
ListNode(int x) {
val = x;
}
}
public static void main(String[] args) {
Solution s = new Solution();
ListNode l1 = new ListNode(1);
l1.next = new ListNode(3);
l1.next.next = new ListNode(5);
l1.next.next.next = new ListNode(8);
ListNode l2 = new ListNode(1);
l2.next = new ListNode(2);
l2.next.next = new ListNode(3);
l2.next.next.next = new ListNode(6);
ListNode res = s.mergeTwoLists(l1, l2);
System.out.println(res);
}
public ListNode mergeTwoLists(ListNode l1, ListNode l2) {
if (l1 == null) {
return l2;
}
if (l2 == null) {
return l1;
}
ListNode root = new ListNode(0);
ListNode temp = root;
ListNode m = l1;
ListNode n = l2;
while (m != null && n != null) {
if (m.val > n.val) {
temp.next = n;
n = n.next;
} else {
temp.next = m;
m = m.next;
}
temp = temp.next;
}
if (m != null) { // so n is null
temp.next = m;
}
if (n != null) { // so m is null
temp.next = n;
}
return root.next;
}
}