hdu 1710 Binary Tree Traversals

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做了vijos 1132之后做这题轻松多了，稍微调试了下就ac了，关键就是通过递归去找节点

前+中->后

#include<iostream>
#include<malloc.h>
#define maxn 1000+5
using namespace std;
int n;
int qi[maxn],zh[maxn];
int t=0;
struct root
{
	int num;
	root *left,*right;
};
void build(root* &s,int as,int ae,int bs,int be)
{
	s=(root*)malloc(sizeof(root));
	s->num=qi[as];
	s->left=s->right=NULL;
	int x=bs;
	while(zh[x]!=qi[as]) x++;
	int l=x-bs;
	if(x>bs) build(s->left,as+1,as+l,bs,x-1); 
	if(x<be) build(s->right,as+l+1,ae,x+1,be);
}
void pi(root *s)
{
	if(s!=NULL)
	{
		pi(s->left);
		pi(s->right);
		if(!t) cout<<s->num;
		else cout<<" "<<s->num;
		t++;
	}
}
int main()
{
	while(cin>>n)
	{
		t=0;
		for(int i=1;i<=n;i++) cin>>qi[i];
		for(int i=1;i<=n;i++) cin>>zh[i];
		root *head;
		build(head,1,n,1,n);
		pi(head);
		cout<<endl;
	}
	return 0;
} 

hdu 1710 Binary Tree Traversals

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原文地址：http://blog.csdn.net/zafkiel_nightmare/article/details/45419421