lesson19-3 以孩子兄弟链表为存储结构，请设计递归和非递归算法求树的深度

思路：

firstchild对应lchild

nextsibling对应rchild

其他操作和普通二叉树的操作一样

代码：

int getHeight(BTNode *t){//递归算法
	if(!t)
		return 0;
	int hc=getHeight(t->firstchild);
	int hs=getHeight(t->nextsibling);
	return (hc+1)>hs?hc+1:hs;
}

int getHeight_(BTNode *t){//非递归算法，层次遍历思想
	BTNode *que[MAXSIZE];
	int front=-1,rear=-1;
	int level=0,last=0;
	rear=(rear+1)%MAXSIZE;
	que[rear]=t;
	BTNode *p;
	while(front!=rear){
		front=(front+1)%MAXSIZE;
		p=que[front];
		if(p->firstchild){
			rear=(rear+1)%MAXSIZE;
			que[rear]=p->firstchild;
		}
		if(p->nextsibling){
			rear=(rear+1)%MAXSIZE;
			que[rear]=p->nextsibling;
		}
		if(front==last){//最右结点出队
			level++;
			last=rear;//当这一层结点都入队后，把rear赋值给last
		}
	}
	return level;
}

测试：

#include<stdio.h>
#include <stdlib.h>
#include<math.h>	//数学函数，求平方根、三角函数、对数函数、指数函数...
 
#define MAXSIZE 100
 
//用于使用c++的输出语句
#include<iostream>
using namespace std;

typedef struct BTNode    
{
	char data;
	struct BTNode *firstchild;
	struct BTNode *nextsibling;
}BTNode;

void createBiTree(BTNode* &T);
int getHeight(BTNode *t);
int getHeight_(BTNode *t);

void main(){
	BTNode *t;
	createBiTree(t);

	cout<<endl;
	cout<<getHeight(t)<<endl;
	cout<<getHeight_(t)<<endl;
}

int getHeight(BTNode *t){//递归算法
	if(!t)
		return 0;
	int hc=getHeight(t->firstchild);
	int hs=getHeight(t->nextsibling);
	return (hc+1)>hs?hc+1:hs;
}

int getHeight_(BTNode *t){//非递归算法，层次遍历思想
	BTNode *que[MAXSIZE];
	int front=-1,rear=-1;
	int level=0,last=0;
	rear=(rear+1)%MAXSIZE;
	que[rear]=t;
	BTNode *p;
	while(front!=rear){
		front=(front+1)%MAXSIZE;
		p=que[front];
		if(p->firstchild){
			rear=(rear+1)%MAXSIZE;
			que[rear]=p->firstchild;
		}
		if(p->nextsibling){
			rear=(rear+1)%MAXSIZE;
			que[rear]=p->nextsibling;
		}
		if(front==last){//最右结点出队
			level++;
			last=rear;//当这一层结点都入队后，把rear赋值给last
		}
	}
	return level;
}

void createBiTree(BTNode* &T)
{
	char  ch;
	cin>>ch;
	if(ch=='#') T=NULL;
	else
	{
		T=(BTNode *)malloc(sizeof(BTNode));
		T->data=ch;
		cout<<"put in \'"<<T->data<<"\' lchild"<<endl;
		createBiTree(T->firstchild);
		cout<<"put in \'"<<T->data<<"\' rchild"<<endl;
		createBiTree(T->nextsibling);
	}
}