108. 将有序数组转换为二叉搜索树
108. 将有序数组转换为二叉搜索树
题目：
题解：
java
复制代码
/**
* Definition for a binary tree node.
* public class TreeNode {
* int val;
* TreeNode left;
* TreeNode right;
* TreeNode() {}
* TreeNode(int val) { this.val = val; }
* TreeNode(int val, TreeNode left, TreeNode right) {
* this.val = val;
* this.left = left;
* this.right = right;
* }
* }
*/
class Solution {
TreeNode conTree(int l, int r, int[] nums) {
if(l>r) {
return null;
}
int mid = (l+r)/2;
TreeNode node = new TreeNode(nums[mid]);
node.left = conTree(l,mid-1,nums);
node.right = conTree(mid+1,r,nums);
return node;
}
public TreeNode sortedArrayToBST(int[] nums) {
return conTree(0,nums.length-1,nums);
}
}
148. 排序链表
148. 排序链表
题目：
题解：
java
复制代码
/**
* Definition for singly-linked list.
* public class ListNode {
* int val;
* ListNode next;
* ListNode() {}
* ListNode(int val) { this.val = val; }
* ListNode(int val, ListNode next) { this.val = val; this.next = next; }
* }
*/
class Solution {
public ListNode sortList(ListNode head) {
if(head==null) {
return head;
}
ListNode cur = head;
List<Integer> list = new ArrayList<>();
while(cur!=null) {
list.add(cur.val);
cur = cur.next;
}
list.sort(null);
ListNode node = new ListNode();
cur = node;
for(int i=0;i<list.size();i++) {
cur.val=list.get(i);
if(i!=list.size()-1) {
cur.next = new ListNode();
}
else {
cur.next = null;
}
cur = cur.next;
}
return node;
}
}