1064 Complete Binary Search Tree

正向思维硬解得分28,最初不知道中序遍历如何解,测试点3不思考为啥错误了

1064 Complete Binary Search Tree

#include <cstdio>
#include <algorithm>
#include <cmath>
#include <queue>
#include <vector>
using namespace std;
const int maxn = 1010;
int orinOrder[maxn],N;
vector<int> orderCBT,levelOrder;

struct node
{
    int data;
    node *lchild, *rchild;
};

node* newNode(int dataX)
{
    node* root = new node;
    root->data = dataX;
    root->lchild = root->rchild = NULL;
    return root;
}

void insert(node* &root,int dataX)
{
    if(root == NULL)
    {
        root = newNode(dataX);
        return;
    }
    if(root->data == dataX) return;
    else if(root->data > dataX) insert(root->lchild,dataX);
    else insert(root->rchild,dataX);
}

node* create()
{
    node* root = newNode(orderCBT[0]);
    for(int i = 0; i < N; i++)
    {
        insert(root,orderCBT[i]);
    }
    return root;
}

void createCBT(int L,int R)
{
    if(L > R) return;
    int len;
    if(L != 0 and R != N) len = R - L + 1;
    else len = R - L;
    double tempExp = log(double(len) + 1.0) / log(2.0);
    int exp = tempExp;
    int rest = len - (int)pow(2.0,exp) + 1;
    int addition;
    if(rest <= 0)
    {
        addition = (int)pow(2.0,exp - 1) - 1;
        if(addition < 0) addition = 0;
    }
    else if(rest >= (int)pow(2.0,exp - 1))
    {
        addition = (int)pow(2.0,exp) - 1;
    }
    else addition = (int)pow(2.0,exp - 1) - 1 + rest;
    int pos = L + addition;
    orderCBT.push_back(orinOrder[pos]);
    createCBT(L,pos - 1);
    createCBT(pos + 1,R);
}

void BFS(node* root)
{
    queue<node*> q;
    q.push(root);
    node* tempRoot;
    while(!q.empty())
    {
        tempRoot = q.front();
        q.pop();
        levelOrder.push_back(tempRoot->data);
        if(tempRoot->lchild != NULL) q.push(tempRoot->lchild);
        if(tempRoot->rchild != NULL) q.push(tempRoot->rchild);
        delete(tempRoot);
    }
    for(int i = 0; i < N; i++)
    {
        if(i == 0) printf("%d",levelOrder[i]);
        else printf(" %d",levelOrder[i]);
    }
}
int main()
{
    scanf("%d",&N);
    for(int i = 0; i < N; i++)
    {
        scanf("%d",&orinOrder[i]);
    }
    sort(orinOrder,orinOrder+N);
    createCBT(0,N);
    node* root = create();
    BFS(root);
}

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