226. 翻转二叉树

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class Solution {

    /**
     * @param  TreeNode  $root
     * @return TreeNode
     */
    function invertTree($root) {
        if ($root->left || $root->right) {
            $left = $this->invertTree($root->left);
            $right = $this->invertTree($root->right);
            $root->left = $right;
            $root->right = $left;
        }
        return $root;
    }
		
		//这个也对
		function invertTree2($root) {
        if (!$root) {
            return;
        }
        $left = $this->invertTree($root->left);
        $right = $this->invertTree($root->right);
        printf("root:%d,left:%d,right:%d\n", $root->val, $left->val, $right->val);
        $root->left = $right;
        $root->right = $left;
        return $root;
    }
		
}

copy success
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