LeetCode#199 Binary Tree Right Side View

最新推荐文章于 2024-01-19 11:16:08 发布

原创最新推荐文章于 2024-01-19 11:16:08 发布 · 130 阅读

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本文介绍了一种用于获取二叉树每层最右侧元素的算法实现。通过使用循环队列来跟踪每一层的节点，并在遍历过程中记录每层最右侧的元素值，最终返回这些值构成的序列。

以层为单位，取每层最右（结束）处的元素。

#define SIZE 32
/**
 * Definition for a binary tree node.
 * struct TreeNode {
 *     int val;
 *     TreeNode *left;
 *     TreeNode *right;
 *     TreeNode(int x) : val(x), left(NULL), right(NULL) {}
 * };
 */
class Solution {
public:
    vector<int> rightSideView(TreeNode* root) {
        if(!root)
            return {};
        vector<int> res;
        vector<TreeNode*> Cqueue(SIZE, NULL);
        int front = 0;
        int rear = 1;
        int layerIndex = 0;
        Cqueue[front] = root;
        while(front != rear){
            if(front == (rear+1)%SIZE)
                cout << "FULL!";
            if(Cqueue[front]->left){
                Cqueue[rear] = Cqueue[front]->left;
                rear = (rear+1) % SIZE;
            }
            if(Cqueue[front]->right){
                Cqueue[rear] = Cqueue[front]->right;
                rear = (rear+1) % SIZE;
            }
            if(layerIndex == front){
                res.push_back(Cqueue[layerIndex]->val);
                layerIndex = (rear-1) % SIZE;
            }
            front = (front+1) % SIZE;
        }
        return res;
    }
};