[剑指offer]二叉树的深度

ゞ浴缸里的玫瑰 2021-11-22 09:28 363阅读 0赞

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。

/*
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* p)
    {
        if(p==NULL)return 0;
        return max(TreeDepth(p->left),TreeDepth(p->right))+1;
    }
};
//非递归写法：层次遍历
class Solution {
public:
    int TreeDepth(TreeNode* p)
    {
        if(p==NULL)return 0;
        queue<TreeNode*> q;
        q.push(p);
        int depth = 0, count = 0, nextCount = 1;
        while(q.size()!=0){
            TreeNode *pTop = q.front();
            q.pop();
            count++;
            if(pTop->left != NULL){
                q.push(pTop->left);
            }
            if(pTop->right != NULL){
                q.push(pTop->right);
            }
            if(count == nextCount){
                nextCount = q.size();
                count = 0;
                depth++;
            }
        }
        return depth;
    }
};