层次建树(优先插入左端),求二叉树的深度

#include<iostream>
#include<string>
#include<unordered_map>
#include<queue>

using namespace std;
struct TreeNode{
    char val;
    int level;
    int height;
    struct TreeNode* left;
    struct TreeNode* right;
    TreeNode(char x,int lev) :val(x), level(lev), height(1),left(nullptr),right(nullptr){}
};

typedef pair<char, int> Pair;
struct cmpbyvalue{
    bool operator ()(const Pair& v1, const Pair &v2){
        return v1.second < v2.second;
    }
};

void create(TreeNode*&root, vector<Pair>& test){//层次建树,利用队列和节点层数来建立
    queue<TreeNode*> que_temp;
    TreeNode* cur=nullptr;
    for (size_t i = 0; i < test.size();i++){
        TreeNode* t = new TreeNode(test[i].first,test[i].second);
        que_temp.push(t);
        if (cur == nullptr)          //只有第一次调用会执行
            cur = que_temp.front();
        if (cur->left != nullptr&&cur->right != nullptr){//注意队列中已经排好序了,如果当前节点的左右孩子都不为空了(不能插入),需要从队列获取一个新的结点
            que_temp.pop();
            cur = que_temp.front();
        }
        if (i == 0){
            root = t;
        }
        else if ((t->level-cur->level==1)&&cur->left==nullptr){//插入到左子树
            cur->left = t;
        }
        else if ((t->level - cur->level == 1)//插入到右子树
            && cur->right == nullptr){
            cur->right = t;
        }
        else{
            que_temp.pop();
            cur = que_temp.front();
            if (cur->left != nullptr)
                cur->left = t;
            else
                cur->right = t;            
        }
    }
}

int count(TreeNode*& root){//统计所有节点的高度并记录到节点的height中
    if (root->left == nullptr&&root->right == nullptr){
        root->height = 1;
        return 1;
    }
    if (root->left != nullptr&&root->right!=nullptr){
        root->height = max(count(root->left), count(root->right)) + 1;
    }
    else if (root->left != nullptr){
        root->height = count(root->left) + 1;
    }
    else{
        root->height = count(root->right) + 1;
    }
    return root->height;
}

TreeNode* print(TreeNode* root,char ch,TreeNode* &point){
    if (root == nullptr)
        return nullptr;
    if (root->val == ch){
        cout << root->height;
        point = root;
        return point;
    }
    return print(root->left, ch,point);
    return print(root->right, ch,point);
}

void Preorder(TreeNode*& root){//先序遍历
    if (root == nullptr)
        return;
    static int count = 1;
    if (root != nullptr){
        cout << "节点" << count++ << ":" << root->val <<" 层次"<<root->level<<"高度:"<<root->height<< endl;
    }
    Preorder(root->left);
    Preorder(root->right);
}

int main(){
    string str1,str2;
    
    while (getline(cin, str1) && getline(cin, str2) && !(str1.size() == 0 && str2.size() == 0)){
        size_t start = 0;
        unordered_map <char, int> que;
        while (start < str1.size()){
            char data = str1[start];
            start++;
            int leve = 0;
            while (str1[start] <= '9'&&str1[start] >= '0'){
                leve = leve * 10 + str1[start] - '0';
                start++;
            }
            que[data] = leve;
        }
        vector<Pair> test(que.begin(), que.end());
        sort(test.begin(), test.end(), cmpbyvalue());
        TreeNode* root = nullptr;
        create(root, test);
        count(root);
        TreeNode* point = nullptr;
        int tem = 0;
        for (size_t s1 = 0; s1 < str2.size(); s1++){
            point=print(root, str2[s1],point);
            if (point ==nullptr)
                cout << tem;
            if (s1!=str2.size()-1)
                cout << " ";
        }
        cout << endl;
    }
    return 0;
}
好像忘记了去释放new出来的内存
手里拿着一把锤子,看什么都像钉子,编程界的锤子应该就是算法了吧!
原文地址:https://www.cnblogs.com/chess/p/5312658.html