题解 | #从上往下打印二叉树#

/**
 * struct TreeNode {
 *	int val;
 *	struct TreeNode *left;
 *	struct TreeNode *right;
 * };
 *
 * C语言声明定义全局变量请加上static，防止重复定义
 */
/**
 * 代码中的类名、方法名、参数名已经指定，请勿修改，直接返回方法规定的值即可
 *
 * 
 * @param root TreeNode类 
 * @return int整型一维数组
 * @return int* returnSize 返回数组行数
 */
int *PrintFromTopToBottom(struct TreeNode *root, int *returnSize)
{
  int *num, pos = 0;
  num = (int *)malloc(sizeof(int) * 1001);
  *returnSize = pos;
  if (!root)
    return num;
  struct TreeNode *que[1000], *temp;
  int front = 0, rear = 0;
  que[++rear] = root;
  while (rear != front)
  {
    temp = que[++front];
    num[pos++] = temp->val;
    if (temp->left)
      que[++rear] = temp->left;
    if (temp->right)
      que[++rear] = temp->right;
  }

  *returnSize = pos;
  return num;
}