Cracking The Coding Interview 4.1

//Implement a function to check if a tree is balanced. For the purposes of this question, a balanced tree is defined to be a tree such that no two leaf nodes differ in distance from the root by more than one.
//
//	译文：
//
//	实现一个函数检查一棵树是否平衡。对于这个问题而言， 平衡指的是这棵树任意两个叶子结点到根结点的距离之差不大于1。

#include <iostream>
#include <string>
using namespace std;

class tree
{
public:

tree()
{
//root = create();
root = NULL;
index = 0;
}

/***输入扩展层次遍历序列，#表示该节点为空***/
tree(char *s)
{
root = NULL;
index = 0;
if (s == NULL)
{
return;
}

int size = strlen(s);
create(&root,s,0,size);
}

~tree()
{
/***清空二叉树***/
}

/***二叉排序树：插入。***/
void insert(char *s)
{
if (s == NULL)
{
return;
}

int size = strlen(s);
for (int i = 0; i<size; i++)
{
insert(&root, s[i]);
}
}

bool isBanlance(int size)
{
int *s = new int[size];
depth(root,s,size,0);
s[index+1] = '\0';
int i = 0;
int max = s[0];
int min = s[0];
while(s[i]!='\0')
{
if (s[i]>max)
{
max = s[i];
}
if (s[i]<min)
{
min = s[i];
}
i++;
}
return ((max - min)>1? 0:1);
}

void preOrder(){	pOrder(root);}
void inOreder(){	zOrder(root);}
void postOreder(){  hOrder(root);}

private:
struct treenode
{
char data;
treenode * left;
treenode * right;
};

treenode *root;
int index;

void insert(treenode **p, char s)
{
if (((*p) == NULL) && s != '\0')
{
*p = new treenode;
(*p)->data = s;
(*p)->left = NULL;
(*p)->right = NULL;
}
else
{
if ((*p)->data > s)
{
insert(&((*p)->left) , s);
}
else
{
insert(&((*p)->right) , s);
}
}
}

void depth(treenode *s, int *str,int size,int k)
{
if (s==NULL)
{
return;
}
if (s->left == NULL && s->right == NULL)
{
str[index]= k;
index++;
}
else
{
depth(s->left,str, size, k+1);
depth(s->right,str, size, k+1);
}
}

treenode* create()
{
treenode *p;
char t;
cout<<"请输入："<<endl;
t = getchar();
if (t=='#')
{
p = NULL;
}
else
{
p = new treenode;
p->data = t;
cout<<"create tree node:  "<<t<<endl;
p->left = create();
p->right = create();

}
return p;
}

void create(treenode **p, char *str, int i, int size)
{

if (i>size-1 || str[i] == '\0')
{
*p = NULL;
return;
}

if (str[i] == '#')
{
*p=NULL;
}
else
{
*p = new treenode;
(*p)->data = str[i];
create(&((*p)->left),str,2*i+1,size);
create(&((*p)->right),str,2*i+2,size);
}
}

void pOrder(treenode *p)
{
if (p==NULL)
{
return;
}

cout<<p->data<<"  "<<endl;
pOrder(p->left);
pOrder(p->right);
}

void zOrder(treenode *p)
{
if (p==NULL)
{
return;
}
zOrder(p->left);
cout<<p->data<<"  "<<endl;
zOrder(p->right);
}

void hOrder(treenode *p)
{
if (p==NULL)
{
return;
}
hOrder(p->left);
cout<<p->data<<"  "<<endl;
hOrder(p->right);
}
};

int main()
{
/***扩展层次序列简立树***/
//char t[9] = "ABCDE#FG";
//tree s(t);
//s.preOrder();

/***建立二叉排序树***/
tree s;
char t[8] = "3289654";
s.insert(t);
//	s.postOreder();

cout<<"is Banlance? "<<s.isBanlance(8)<<endl;
cout<<"Over"<<endl;

return 0;
}