二叉查找树——A1043.Is it a Binary Search Tree(25)

Posted 2020-11-25 jasonpeng1

 

 

#include <bits/stdc++.h>
#include <stdio.h>
#include <stdlib.h>
#include <queue>
using namespace std;
struct node{
    int data;
    node *left;
    node *right;
};
void insert(node* &root,int data){
    if(root == NULL){
        root = new node;
        root->data = data;
        root->left = NULL;
        root->right = NULL;
    }
    else if(data < root->data){
        insert(root->left,data);
    }else{
        insert(root->right,data);
    }
}
void preOrder(node* root,vector<int>& temppreorder){
    if(root == NULL){
        return;
    }
    temppreorder.push_back(root->data);
    preOrder(root->left,temppreorder);
    preOrder(root->right,temppreorder);
}
void preMirro(node* root,vector<int>& tempMirrorder){
    if(root == NULL){
        return;
    }
    tempMirrorder.push_back(root->data);
    preMirro(root->right,tempMirrorder);
    preMirro(root->left,tempMirrorder);
}
void postOrder(node* root,vector<int>& postorder){
    if(root == NULL){
        return;
    }
    postOrder(root->left,postorder);
    postOrder(root->right,postorder);
    postorder.push_back(root->data);
}
void postMirrOrder(node* root,vector<int>& postMirrorder){
    if(root == NULL){
        return;
    }
    postMirrOrder(root->right,postMirrorder);
    postMirrOrder(root->left,postMirrorder);
    postMirrorder.push_back(root->data);
}
int main(){
    int n;
    vector<int> initial,postorder,postMirrorder;
    vector<int> temppreorder;
    vector<int> tempMirrorder;
    scanf("%d",&n);
    node *root = NULL;
    int t;
    for(int i =0;i<n;++i){
        scanf("%d",&t);
        initial.push_back(t);
        insert(root,t);
    }
    preOrder(root,temppreorder);
    preMirro(root,tempMirrorder);
    bool order = true,mirrOrder = true;
    for(int i = 0;i<initial.size();++i){
        if(initial[i] != temppreorder[i]){
            order = false;
        }
        if(initial[i] != tempMirrorder[i]){
            mirrOrder = false;
        }
    }
    /* 
    for(int i=0;i<initial.size();++i){
        if(i != initial.size()-1){
            printf("%d",initial[i]);
        }else{
            printf("%d
",initial[i]);
        }
    }
    for(int i=0;i<temppreorder.size();++i){
        if(i != temppreorder.size()-1){
            printf("%d",temppreorder[i]);
        }else{
            printf("%d
",temppreorder[i]);
        }
    }*/
    /*for(int i=0;i<tempMirrorder.size();++i){
        if(i != tempMirrorder.size()-1){
            printf("%d",tempMirrorder[i]);
        }else{
            printf("%d
",tempMirrorder[i]);
        }
    }*/ 
    if(order == true){
        printf("YES
");
        postOrder(root,postorder);
        for(int i = 0;i<postorder.size();++i){
            if(i != postorder.size()-1){
                printf("%d ",postorder[i]);
            }else{
                printf("%d",postorder[i]);
            }
        }
    }
    else if(mirrOrder == true){
        printf("YES
");
        postMirrOrder(root,postMirrorder);
        for(int i = 0;i<postMirrorder.size();++i){
            if(i != postMirrorder.size()-1){
                printf("%d ",postMirrorder[i]);
            }else{
                printf("%d",postMirrorder[i]);
            }
        }
    }else{
        printf("NO
");
    }
    system("pause");
    return 0;
}