1064. Complete Binary Search Tree (30)

注意點：

1.直接把樹放在數組裏，不要用指針建樹

#include<cstdio>
#include<iostream>
#include<string>
#include<algorithm>
#include<map>
#include<sstream>
using namespace std;
int a[1000];
int b[1000];
int N;
int Exchange(int num){
	int i=1,count=0;
	while(count+i<=num){
		count+=i;
		i*=2;
	}
	if(num-count>=i/2)
	return count;
	return num-1-(count-1)/2;
}
void BuildTree(int N,int top,int begin){
	int t=Exchange(N);
	b[top]=a[t+begin];
	if(t!=0)
	BuildTree(t,2*top,begin);
	if(t!=N-1)
	BuildTree(N-1-t,2*top+1,t+1+begin);
}
int main(){
	int i;
	cin>>N;
	for(i=0;i<N;i++)
	cin>>a[i];
	sort(a,a+N); 
	BuildTree(N,1,0);
	for(i=1;i<=N;i++){
		if(i!=1)
		cout<<" ";
		cout<<b[i];
	}
}