按输入顺序建立二叉搜索树，并搜索某一结点，输出其父结点。

输入格式:

输入有三行：
第一行是n值，表示有n个结点；
第二行有n个整数，分别代表n个结点的数据值；
第三行是x，表示要搜索值为x的结点的父结点。

输出格式:

输出值为x的结点的父结点的值。
若值为x的结点不存在，则输出：It does not exist.
若值为x的结点是根结点，则输出：It doesn't have parent.

输入样例:

2
20
30
20

输出样例:

It doesn't have parent.

###输入样例：

2
20
30
30

输出样例:

20

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提交结果： 

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思路分析：

        创建树，查找元素，设置一个指针指向查找的结点的父节点。（这道题我自己写，提交全是段错误，然后喂给文心一言，给我改了一下，过了俩检查点，我自己在文心一言给出结果上面改，最后全过了，离谱！）

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初始代码（段错误版）：含有老师PPT代码

//
// Created by DDD on 2023/12/20.
//
#include <stdio.h>
#include <malloc.h>typedef struct BiTNode
{int data;struct BiTNode *lchild,*rchild;
}BiTNode;void Init(BiTNode *t,int x){t->data = x;t->rchild = NULL;t->lchild = NULL;
}BiTNode *insertNode(BiTNode *t,BiTNode *s){BiTNode *p,*q;if(t==NULL)return s;p = t;while (p){q = p;if(s->data == p->data)return t;if(s->data < p->data)p = p->rchild;else p = p->rchild;}if(s->data<q->data)q->lchild = s;else q->rchild = s;return t;
}void Search(BiTNode *Head,int x){BiTNode *p,*q;p = Head;if(Head == NULL){printf("It does not exist.");return;}if(Head->data == x) {printf("It doesn't have parent.");return;}while(p){if(x == p->data){printf("%d",q->data);return;}q = p;if(x>p->data)p = p->rchild;else p=p->lchild;}printf("It does not exist.");
}int main(){int n,x;scanf("%d",&n);BiTNode *SearchTree;scanf("%d",&x);Init(SearchTree,x);for (int i = 0; i < n-1; ++i) {scanf("%d",&x);BiTNode *insert = (BiTNode *) malloc(sizeof(BiTNode));Init(insert,x);SearchTree = insertNode(SearchTree,insert);}scanf("%d",&x);Search(SearchTree,x);
}

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结果版代码：具有人工智能（人工+智能）的美感

#include <stdio.h>
#include <stdlib.h>typedef struct BiTNode
{int data;struct BiTNode *lchild, *rchild;
} BiTNode;void Init(BiTNode *t, int x) {t->data = x;t->lchild = t->rchild = NULL;
}BiTNode *insertNode(BiTNode *t, BiTNode *s) {if (t == NULL) {t = (BiTNode *)malloc(sizeof(BiTNode));Init(t, s->data);return t;}if (s->data < t->data) {t->lchild = insertNode(t->lchild, s);} else if (s->data > t->data) {t->rchild = insertNode(t->rchild, s);}else if(s->data == t->data){return t;}// If data is same, you may choose to insert or not, based on your requirements.return t;
}void Search(BiTNode *Head, int x) {BiTNode *q;if (Head == NULL) {printf("It does not exist.\n");return;}if (Head->data == x) {printf("It doesn't have parent.\n");return;}BiTNode *p = Head;while (p) {if (x == p->data) {printf("%d\n", q->data);return;}q = p;if (x < p->data) {p = p->lchild;} else {p = p->rchild;}}printf("It does not exist.\n");
}int main() {int n, x;scanf("%d", &n);BiTNode *root = NULL; // Initialize the root as NULL. This will be our SearchTree.scanf("%d", &x);root = (BiTNode *)malloc(sizeof(BiTNode)); // Allocate memory for the root node.Init(root, x); // Initialize the root node.for (int i = 0; i < n - 1; ++i) {scanf("%d", &x);BiTNode *insert = (BiTNode *)malloc(sizeof(BiTNode)); // Allocate memory for the new node.Init(insert, x); // Initialize the new node.root = insertNode(root, insert); // Insert the new node into the binary search tree.}scanf("%d", &x);Search(root, x);free(root);return 0;
}

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return -1；