leetcode练习题

#include <iostream>
#include <queue>
#include <vector>
using namespace std;
/**
 * 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) {}
 * };
 */
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> levelOrder(TreeNode* root) {
        vector<int> result;
        if(root == nullptr) {
            return result;
        }
        queue<TreeNode*> que;
        int depth = 1;
        que.push(root);
        while (!que.empty()) {
            int count = que.size();
            int curLevelMax = INT_MIN;
            while(count > 0) {
                TreeNode* node = que.front();
                que.pop();
                curLevelMax = node->val > curLevelMax ? node->val : curLevelMax;
                if(node->left)
                    que.push(node->left);
                if(node->right)
                    que.push(node->right);
                count--;
            }
            result.push_back(curLevelMax);
        }
        return result;
    }

    vector<int> getIndex(TreeNode *root, vector<int> target) {
        // 先进行bfs
        vector<int> bfs_result = levelOrder(root);
        //打印bfs结果
        cout << "bfs result :" << endl;
        for(auto each_col : bfs_result) {
            cout << each_col << " " << endl;
        }

        // 然后依次比较
        vector<int> index_result;
        int cur_max_depth = -1;
        for(auto each_targe : target) {
            for(int i = bfs_result.size() - 1; i >= 0; i--) {
                if(bfs_result[i] > each_targe) {
                    cur_max_depth = i+1;
                    break;
                }
            }
            index_result.push_back(cur_max_depth);
            cur_max_depth = -1;
        }
        return index_result;
    }
};

int main() {
    std::cout << "Hello, World!" << std::endl;
    TreeNode root(3);
    TreeNode l1_1(4);
    TreeNode l1_2(11);
    TreeNode l2_1(3);
    TreeNode l2_2(8);
    TreeNode l3_1(7);
    TreeNode l3_2(5);
    root.left = &l1_1;
    root.right = &l1_2;
    l1_1.left = &l2_1;
    l1_2.right = &l2_2;
    l2_1.left = &l3_1;
    l2_2.right = &l3_2;
    Solution s1;
    vector<int> target = {6,2,9,7,9};
    vector<int> com_result =s1.getIndex(&root, target);
    cout <<  "result " << endl;
    for(auto each : com_result)
        cout << each << " ";
    return 0;
}