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This time I will bring you a detailed explanation of the steps to obtain a binary tree image with PHP. What are the precautions for PHP to obtain a binary tree image. The following is a practical case, let's take a look.
Question
Manipulate the given binary tree and transform it into a mirror image of the source binary tree.
Solution idea
There are two ways to flip the binary tree: recursive and non-recursive. Non-recursive is to use queue.
Implementation code
<?php /*class TreeNode{ var $val; var $left = NULL; var $right = NULL; function construct($val){ $this->val = $val; } }*/ function Mirror(&$root) { if($root == NULL) return 0; $queue = array(); array_push($queue, $root); while(!empty($queue)){ $node = array_shift($queue); $tmp = $node->left; $node->left = $node->right; $node->right = $tmp; if($node->left != NULL) array_push($queue, $node->left); if($node->right != NULL) array_push($queue, $node->right); } }I believe you have mastered the method after reading the case in this article. For more exciting information, please pay attention to other related articles on the PHP Chinese website! Recommended reading:
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