力扣-199题二叉树的右视图（C++）- 层序遍历

r囧r小猫 2022-09-02 03:54 130阅读 0赞

题目链接：[https://leetcode-cn.com/problems/binary-tree-right-side-view/][https_leetcode-cn.com_problems_binary-tree-right-side-view]  
题目如下：  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQwNDY3Njcw_size_16_color_FFFFFF_t_70]  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQwNDY3Njcw_size_16_color_FFFFFF_t_70 1]

/**
     * Definition for a binary tree node.
     * struct TreeNode {
     *     int val;
     *     TreeNode *left;
     *     TreeNode *right;
     *     TreeNode() : val(0), left(nullptr), right(nullptr) {}
     *     TreeNode(int x) : val(x), left(nullptr), right(nullptr) {}
     *     TreeNode(int x, TreeNode *left, TreeNode *right) : val(x), left(left), right(right) {}
     * };
     */
    class Solution {
        
    public:
        vector<int> rightSideView(TreeNode* root) {
        
            vector<int> result;
            if(!root) return result;
            queue<TreeNode*> que;
            que.push(root);
    
            while(!que.empty()){
        
                int size=que.size();
                int temp;
                
                while(size--){
        //当前层
                    TreeNode* node=que.front();
                    que.pop();
                    temp=node->val;
                    
                    if(node->left) que.push(node->left);
                    if(node->right) que.push(node->right);  
                }
    
                result.push_back(temp);
            }
    
            return result;
        }
    };

[https_leetcode-cn.com_problems_binary-tree-right-side-view]: https://leetcode-cn.com/problems/binary-tree-right-side-view/
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQwNDY3Njcw_size_16_color_FFFFFF_t_70]: /images/20220829/b985da7304b5448f84731a47a4e8457f.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQwNDY3Njcw_size_16_color_FFFFFF_t_70 1]: /images/20220829/a078454524b3458599143e948f5f8340.png