二叉搜索树的实现和前序遍历

来源：互联网发布：sql 链接查询结果编辑：程序博客网时间：2024/05/16 10:36
    #include <algorithm>    #include <iostream>    #include <iterator>    #include <sstream>    #include <fstream>    #include <istream>    #include <ostream>    #include <complex>    #include <cstring>    #include <utility>    #include <cstdlib>    #include <cstdio>    #include <vector>    #include <string>    #include <cctype>    #include <ctime>    #include <cmath>    #include <queue>    #include <stack>    #include <list>    #include <new>    #include <set>    #include <map>    using namespace std;    typedef pair<int, int> pii;    typedef long long int LL;    const int INF = 0x3f3f3f3f;    const int maxn = 10005;    struct Node{        int value;        Node *lc, *rc;    };    Node* Insert(Node *root, int x){//把x插入到搜索树中        if (!root){            Node *p = new Node();            p->value = x;            p->lc = p->rc = NULL;            return p;        }else{            if (x < root->value)                root->lc = Insert(root->lc, x);            else root->rc = Insert(root->rc, x);            return root;        }    }    bool Find(Node *root, int x){//判断x是否在搜索树中        if (!root) return false;        else if (x == root->value) return true;        else if (x > root->value) return Find(root->rc, x);        else return Find(root->lc, x);    }    Node* Delete(Node *root, int x){//从搜索树中删除x        if (!root) return NULL;        if (x > root->value) root->rc = Delete(root->rc, x);        else if (x < root->value) root->lc = Delete(root->lc, x);        else if (root->lc == NULL){//如果左儿子为空，就把右儿子提上去            Node *p = root->rc;            delete root;            return p;        }        else if (root->lc->rc == NULL){//如果左儿子没有右儿子，就把左儿子提上去            Node *p = root->lc;            p->rc = root->rc;            delete root;            return p;        }        else{//在左儿子的后代中找到一个最大的节点，把它提上去当父亲            Node *p;            for (p = root->lc; p->rc->rc != NULL; p = p->rc);            Node *r = p->rc;            p->rc = r->lc;            r->lc = root->lc;            r->rc = root->rc;            delete root;            return r;        }        return root;    }    Node* Build_BST(int *a, int n){//输入数组，建立二叉搜索树        srand((unsigned)time(0));//如果数组是有序的，搜索树就会退化成一个链表，所以我们先随机打乱数组顺序        int r = rand() % n;        swap(a[0], a[r]);        Node *root = NULL;        for (int i = 0; i < n; i++)            root = Insert(root, a[i]);        return root;    }    void Inorder_view(Node *root){        if (root){            if (root->lc) Inorder_view(root->lc);            printf("%d\n", root->value);            if (root->rc) Inorder_view(root->rc);        }    }    int main()    {        //freopen("1.txt", "r", stdin);        int a[maxn], n;        cin >> n;        for (int i = 0; i < n; i++)            cin >> a[i];        Node *root = Build_BST(a, n);        root = Delete(root, 5);        Inorder_view(root);        root = Delete(root, 6);        Inorder_view(root);        return 0;    }
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