重建二叉树与二叉树的层次遍历

题目描述

输入

输出

示例输入

2
abdegcf
dbgeafc
xnliu
lnixu

示例输出

dgebfca
abcdefg
linux
xnuli

#include<stdio.h>
#include<iostream>
#include<cstring>
#include<queue>
#include<algorithm>
usingnamespacestd;
typedefstructnode
{
	chardata;
	node*lch,*rch;
}btree,*bt;
charpre[55],ins[55];
voidbuild(bt&T,char*pre,char*ins,intn)//根据先序和中序重建二叉树
{
	if(n<=0)T=NULL;
	else
	{
		intk=strchr(ins,pre[0])-ins;
		T=newbtree;
		T->data=pre[0];
		build(T->lch,pre+1,ins,k);
		build(T->rch,pre+k+1,ins+k+1,n-k-1);
	}
}
voidlast(btT)//后序遍历
{
	if(T)
	{
		last(T->lch);
		last(T->rch);
		cout<<T->data;

	}
}
voidlevel(btT)//层次遍历(BFS)
{
	queue<btree>Q;
	Q.push(*T);
	while(!Q.empty())
	{
		btreenext=Q.front();
		Q.pop();
		cout<<next.data;
		if(next.lch)Q.push(*(next.lch));
		if(next.rch)Q.push(*(next.rch));
	}
}
intmain()
{
	btroot;
	intn;
	cin>>n;
	getchar();
	while(n--)
	{
		cin>>pre>>ins;
		build(root,pre,ins,strlen(pre));
		last(root);
		cout<<endl;
		level(root);
		cout<<endl;
	}
	return0;
}