[数据结构与算法]求二叉树的宽度与二叉树的层数

用层序遍历来实现，两个问题使用的方法相近；

void BinaryTreeWidth_level(TreeNode* root, int &width, int &height)
{
    if(root == NULL)
    {
        height = 0;
        width = 0;
        return ;
    }
        
    TreeNode* p = root;
    queue<TreeNode*> Q;
    Q.push(p);
    int maxwidth = 0;
    int last_size = 1;  // 记录上一层的结点个数，
    int level = 0;
    while(!Q.empty())
    {
        last_size--;
        if(last_size == 0)
        {
            maxwidth = Q.size() > maxwidth ? Q.size() : maxwidth ;
            last_size = Q.size();
            level++;
        }
        TreeNode* now = Q.front();
        Q.pop();
        if(now->lc != NULL)
            Q.push(now->lc);
        
        if(now->rc != NULL)
            Q.push(now->rc);
    }
    height = level;
    width = maxwidth;
    return ;
}