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二叉树的深度

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输入一棵二叉树，求该树的深度。从根结点到叶结点依次经过的结点（含根、叶结点）形成树的一条路径，最长路径的长度为树的深度。

广搜、一层一层数，以便计层数

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/*
struct TreeNode {
	int val;
	struct TreeNode *left;
	struct TreeNode *right;
	TreeNode(int x) :
			val(x), left(NULL), right(NULL) {
	}
};*/
class Solution {
public:
    int TreeDepth(TreeNode* pRoot)
    {
        if (pRoot == nullptr)
        {
            return 0;
        }
        else
        {
            queue<TreeNode*> q;
            int depth = 0;
            int kids_finished = 0;
            int total_kids = 1;
            q.push(pRoot);
            while (q.size() > 0)
            {
                TreeNode* current = q.front();
                q.pop();
                kids_finished++;
                if (current->left != nullptr)
                {
                    q.push(current->left);
                }
                if (current->right != nullptr)
                {
                    q.push(current->right);
                }
                if (kids_finished == total_kids)
                {
                    depth++;
                    kids_finished = 0;
                    total_kids = q.size();
                }
            }
            return depth;
        }
    }
};