A18429. 以下代码可以正确地按层换行输出二叉树的节点值。void printByLevel(TreeNode* root) { if (!root) return; queue<TreeNode*> q; q.push(root); while (!q.empty()) { for (int i = 0; i < q.size(); ++i) { TreeNode* cur = q.front(); q.…

以下代码可以正确地按层换行输出二叉树的节点值。

void printByLevel(TreeNode* root) {
	if (!root) return;
	queue<TreeNode*> q;
	q.push(root);
	
	while (!q.empty()) {
		for (int i = 0; i < q.size(); ++i) {
			TreeNode* cur = q.front();
			q.pop();
			cout << cur->val << " ";
			
			if (cur->left) q.push(cur->left);
			if (cur->right) q.push(cur->right);
		}
		cout << endl;
	}
}