1064. Complete Binary Search Tree (30)

标签：pat   算法   数据结构   

    递归构建即可。

代码：
        

#include<iostream>
#include<vector> 
#include<cmath>
#include<algorithm>
#include<fstream>
using namespace std;
vector<int>nodes;

/**
    @parm l,r point for nodes
    @parm trees store constructed CBT
    @parm pos position for trees
*/
void buildCBT(int l,int r,const vector<int> &nodes ,vector<int> &trees,int pos){
    if(l>r)return;
    if(l==r){
        trees[pos] = nodes[l];    
    }else {
        int sumNode = r - l +1;
        int level = log((double)sumNode)/log((double)2) +1;
        int lastLevelNodes = pow((double)2,level-1);
        int knodes=lastLevelNodes-1;//除去最后一行的节点数 
        int lastRealNodes = sumNode -knodes;
        int offset =0;
        if(lastRealNodes>=lastLevelNodes/2){
            offset = lastLevelNodes/2;
        }else{
            offset = lastRealNodes;    
        }
        int nodeIndex=l+knodes/2 +offset;
        //cout<<"nodeIndex "<<nodeIndex<<" "<<endl;
        trees[pos] = nodes[nodeIndex];
        //cout<<"trees[pos] "<<trees[pos]<<" ";
        buildCBT(l,nodeIndex-1,nodes,trees,2*pos);
        buildCBT(nodeIndex+1,r,nodes,trees,2*pos+1);         
    }
}

int main(){
    ifstream cin("data.txt");
    int num;
    cin>>num;
    int k;
    for(int i=0;i<num;++i){
        cin>>k;
        nodes.push_back(k);      
    }
    vector<int>trees(num+1);
    sort(nodes.begin(),nodes.end());
    buildCBT(0,num-1,nodes,trees,1);
    for(int i=1;i<trees.size()-1;++i){
        cout<<trees[i]<<" ";    
    }
    cout<<trees[trees.size()-1]<<"\n";
    //system("pause");    
} 

1064. Complete Binary Search Tree (30),布布扣,bubuko.com

1064. Complete Binary Search Tree (30)

标签：pat   算法   数据结构   

原文地址：http://blog.csdn.net/youmengjiuzhuiba/article/details/38678443