1043. Is It a Binary Search Tree (25) PAT甲级

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#include<stdio.h>#include<vector>using namespace std;typedef struct Node{    int data;    struct Node *lchild,*rchild; }BTnode,*BTree;int n;vector<int> ori,pre,preM,post,postM;void insert(BTree &root,int data){    if(root==NULL){        root=new BTnode;        root->data=data;        root->lchild=root->rchild=NULL;        return;    }    if(data<root->data) insert(root->lchild,data);    else insert(root->rchild,data);}void PreOrder(BTree root,vector<int> &v){    if(root==NULL)        return;    v.push_back(root->data);    PreOrder(root->lchild,v);    PreOrder(root->rchild,v);}void PreOrderMirror(BTree root,vector<int> &v){    if(root==NULL)        return;    v.push_back(root->data);    PreOrderMirror(root->rchild,v);    PreOrderMirror(root->lchild,v);}void PostOrder(BTree root,vector<int> &v){    if(root==NULL)        return;    PostOrder(root->lchild,v);    PostOrder(root->rchild,v);    v.push_back(root->data);}void PostOrderMirror(BTree root,vector<int> &v){    if(root==NULL)        return;    PostOrderMirror(root->rchild,v);    PostOrderMirror(root->lchild,v);    v.push_back(root->data);}int main(){    scanf("%d",&n);    int data;    BTree root=NULL;    for(int i=0;i<n;i++){        scanf("%d",&data);        ori.push_back(data);        insert(root,data);    }    PreOrder(root,pre);    PreOrderMirror(root,preM);    PostOrder(root,post);    PostOrderMirror(root,postM);    if(ori==pre){        printf("YES\n");        for(int i=0;i<post.size();i++){            printf("%d",post[i]);            if(i!=post.size()-1)                printf(" ");        }     }    else if(ori==preM){        printf("YES\n");        for(int i=0;i<postM.size();i++){            printf("%d",postM[i]);            if(i!=postM.size()-1)                printf(" ");        }    }    else{        printf("NO\n");    }}
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