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添加0107二叉树的层序遍历II 不需要反转答案的 Java 版本

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Original file line number	Diff line number	Diff line change
`@@ -562,6 +562,45 @@ public class N0107 {`
`562`	`562`	`}`
`563`	`563`	```
`564`	`564`
	`565`	+```java
	`566`	`+/**`
	`567`	`+ * 思路和模板相同, 对收集答案的方式做了优化, 最后不需要反转`
	`568`	`+ */`
	`569`	`+class Solution {`
	`570`	`+ public List<List<Integer>> levelOrderBottom(TreeNode root) {`
	`571`	`+ // 利用链表可以进行 O(1) 头部插入, 这样最后答案不需要再反转`
	`572`	`+ LinkedList<List<Integer>> ans = new LinkedList<>();`
	`573`	`+`
	`574`	`+ Queue<TreeNode> q = new LinkedList<>();`
	`575`	`+`
	`576`	`+ if (root != null) q.offer(root);`
	`577`	`+`
	`578`	`+ while (!q.isEmpty()) {`
	`579`	`+ int size = q.size();`
	`580`	`+`
	`581`	`+ List<Integer> temp = new ArrayList<>();`
	`582`	`+`
	`583`	`+ for (int i = 0; i < size; i ++) {`
	`584`	`+ TreeNode node = q.poll();`
	`585`	`+`
	`586`	`+ temp.add(node.val);`
	`587`	`+`
	`588`	`+ if (node.left != null) q.offer(node.left);`
	`589`	`+`
	`590`	`+ if (node.right != null) q.offer(node.right);`
	`591`	`+ }`
	`592`	`+`
	`593`	`+ // 新遍历到的层插到头部, 这样就满足按照层次反序的要求`
	`594`	`+ ans.addFirst(temp);`
	`595`	`+ }`
	`596`	`+`
	`597`	`+ return ans;`
	`598`	`+ }`
	`599`	`+}`
	`600`	+```
	`601`	`+`
	`602`	`+`
	`603`	`+`
`565`	`604`	`go:`
`566`	`605`
`567`	`606`	```GO
`@@ -3013,4 +3052,3 @@ impl Solution {`
`3013`	`3052`	`<a href="https://programmercarl.com/other/kstar.html" target="_blank">`
`3014`	`3053`	`<img src="../pics/网站星球宣传海报.jpg" width="1000"/>`
`3015`	`3054`	`</a>`
`3016`		`-`

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