107.二叉树的层次遍历-ii.c

/*
 * @lc app=leetcode.cn id=107 lang=c
 *
 * [107] 二叉树的层次遍历 II
 *
 * https://leetcode-cn.com/problems/binary-tree-level-order-traversal-ii/description/
 *
 * algorithms
 * Easy (66.25%)
 * Likes:    286
 * Dislikes: 0
 * Total Accepted:    75.5K
 * Total Submissions: 114K
 * Testcase Example:  '[3,9,20,null,null,15,7]'
 *
 * 给定一个二叉树，返回其节点值自底向上的层次遍历。 （即按从叶子节点所在层到根节点所在的层，逐层从左向右遍历）
 * 
 * 例如：
 * 给定二叉树 [3,9,20,null,null,15,7],
 * 
 * ⁠   3
 * ⁠  / \
 * ⁠ 9  20
 * ⁠   /  \
 * ⁠  15   7
 * 
 * 
 * 返回其自底向上的层次遍历为：
 * 
 * [
 * ⁠ [15,7],
 * ⁠ [9,20],
 * ⁠ [3]
 * ]
 * 
 * 
 */

// @lc code=start
/**
 * Definition for a binary tree node.
 * struct TreeNode {
 *     int val;
 *     struct TreeNode *left;
 *     struct TreeNode *right;
 * };
 */


/**
 * Return an array of arrays of size *returnSize.
 * The sizes of the arrays are returned as *returnColumnSizes array.
 * Note: Both returned array and *columnSizes array must be malloced, assume caller calls free().
 */
int** levelOrderBottom(struct TreeNode* root, int* returnSize, int** returnColumnSizes){

}


// @lc code=end