牛客题霸-二叉树最大深度题解

/**
 * struct TreeNode {
 *	int val;
 *	struct TreeNode *left;
 *	struct TreeNode *right;
 * };
 */

class Solution {
public:
    /**
     * 
     * @param root TreeNode类 
     * @return int整型
     */
    typedef struct{
        TreeNode* val;
        int h;//记录当前结点在第几层//
    }node;
    int maxDepth(TreeNode* root) {
        // write code here
        if(root==NULL)return 0;
        queue<node>q;
        int h;
        q.push({root,1});
        while(!q.empty()){
            node LNode=q.front();
            q.pop();
            TreeNode* top=LNode.val;
            h=LNode.h;
            if(top->left!=NULL){
                node next;
                next.val=top->left;
                next.h=h+1;//左子树层数等于父结点层数加一//
                q.push(next);
            }
            if(top->right!=NULL){
                node next;
                next.val=top->right;
                next.h=h+1;//右子树层数等于父结点层数加一//
                q.push(next);
            }
        }
        return h;//最后出队的结点就是最深结点//
    }
};