重建二叉树与二叉树的层次遍历

2
abdegcf
dbgeafc
xnliu
lnixu

dgebfca
abcdefg
linux
xnuli

#include <stdio.h>
#include <iostream>
#include <cstring>
#include <queue>
#include <algorithm>
using namespace std;
typedef struct node
{
	char data;
	node *lch,*rch;
}btree,*bt;
char pre[55],ins[55];
void build(bt &T,char *pre,char *ins,int n) //依据先序和中序重建二叉树
{
	if(n<=0) T=NULL;
	else
	{
		int k=strchr(ins,pre[0])-ins;
		T=new btree;
		T->data=pre[0];
		build(T->lch,pre+1,ins,k);
		build(T->rch,pre+k+1,ins+k+1,n-k-1);
	}
}
void last(bt T)//后序遍历
{
	if(T)
	{
		last(T->lch);
		last(T->rch);
		cout<<T->data;

	}
}
void level(bt T) //层次遍历(BFS)
{
	queue <btree> Q;
	Q.push(*T);
	while(!Q.empty())
	{
		btree next=Q.front();
		Q.pop();
		cout<<next.data;
		if(next.lch) Q.push(*(next.lch));
		if(next.rch) Q.push(*(next.rch));
	}
}
int main()
{
	bt root;
	int n;
	cin>>n;
	getchar();
	while(n--)
	{
		cin>>pre>>ins;
		build(root,pre,ins,strlen(pre));
		last(root);
		cout<<endl;
		level(root);
		cout<<endl;
	}
	return 0;
}