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Update 0108.将有序数组转换为二叉搜索树.md
更新java的 递归和迭代
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@ -209,6 +209,8 @@ public:
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Java:
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递归: 左闭右开 [left,right)
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```Java
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class Solution {
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public TreeNode sortedArrayToBST(int[] nums) {
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@ -232,6 +234,75 @@ class Solution {
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```
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递归: 左闭右闭 [left,right]
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```java
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class Solution {
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public TreeNode sortedArrayToBST(int[] nums) {
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TreeNode root = traversal(nums, 0, nums.length - 1);
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return root;
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}
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// 左闭右闭区间[left, right)
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private TreeNode traversal(int[] nums, int left, int right) {
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if (left > right) return null;
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int mid = left + ((right - left) >> 1);
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TreeNode root = new TreeNode(nums[mid]);
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root.left = traversal(nums, left, mid - 1);
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root.right = traversal(nums, mid + 1, right);
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return root;
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}
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}
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```
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迭代: 左闭右闭 [left,right]
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```java
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class Solution {
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public TreeNode sortedArrayToBST(int[] nums) {
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if (nums.length == 0) return null;
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//根节点初始化
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TreeNode root = new TreeNode(-1);
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Queue<TreeNode> nodeQueue = new LinkedList<>();
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Queue<Integer> leftQueue = new LinkedList<>();
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Queue<Integer> rightQueue = new LinkedList<>();
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// 根节点入队列
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nodeQueue.offer(root);
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// 0为左区间下表初始位置
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leftQueue.offer(0);
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// nums.size() - 1为右区间下表初始位置
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rightQueue.offer(nums.length - 1);
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while (!nodeQueue.isEmpty()) {
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TreeNode currNode = nodeQueue.poll();
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int left = leftQueue.poll();
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int right = rightQueue.poll();
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int mid = left + ((right - left) >> 1);
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// 将mid对应的元素给中间节点
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currNode.val = nums[mid];
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// 处理左区间
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if (left <= mid - 1) {
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currNode.left = new TreeNode(-1);
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nodeQueue.offer(currNode.left);
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leftQueue.offer(left);
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rightQueue.offer(mid - 1);
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}
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// 处理右区间
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if (right >= mid + 1) {
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currNode.right = new TreeNode(-1);
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nodeQueue.offer(currNode.right);
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leftQueue.offer(mid + 1);
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rightQueue.offer(right);
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}
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}
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return root;
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}
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}
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```
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Python:
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```python3
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# Definition for a binary tree node.
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