我有一个订单5 Btree，包含插入，高度，查找和打印方法。我很难理解如何打印深度的第一个A-Z？我有一个打印功能将显示每个节点和其中的元素，但想了解如何按顺序打印。我更喜欢AVL树。
#include <iostream>
#include <stdlib.h>
#include <string>
using namespace std;
const int MAX = 4 ; //maximum # of keys
const int MIN = 2 ; //minimum # of keys
struct btnode
{
int count ;
string value[MAX + 1] ; //number of elements + 1;
btnode *child[MAX + 1] ;
} ;
class btree
{
private :
btnode *root ;
public :
btree( ) ;
void insert ( string val ) ;
int setValue ( string val, btnode *n, string *p, btnode **c ) ;
static int searchNode ( string val, btnode *n, int *pos ) ;
void fillNode ( string val, btnode *c, btnode *n, int k ) ;
void split ( string val, btnode *c, btnode *n, int k, string *y, btnode **newnode ) ;
void show( ) ;
//void search(string key);
int searchPos(string key,string *key_arr,int n); //sub-function for search
static void display ( btnode *root) ;
// void height(string key);
} ;
btree :: btree( )
{
root = NULL ;
}
int btree :: searchNode ( string val, btnode *n, int *pos ) //searches for string in node
{
if ( val < n -> value[1] )
{
*pos = 0 ;
return 0 ;
}
else
{
*pos = n -> count ;
while ( ( val < n -> value[*pos] ) && *pos > 1 )
( *pos )-- ;
if ( val == n -> value[*pos] ) //if value exists in the node returns
{
for(int j =0; j <= n->count; j++)
{
//cout<<"Test in searchmode function"<<endl;
cout<<n->value[j]<<endl;
}
return 1 ;
}
else
return 0 ;
}
}
void btree :: insert ( string val ) //inputting a string
{
string in ;
btnode *c, *n ;
int flag ;
flag = setValue ( val, root, &in, &c ); //in flag has value
if ( flag )
{
n = new btnode ; //create a new btnode
n -> count = 1 ; //initiates the count to 1
n -> value[1] = in ; //value of our node is set to the String passed in
n -> child[0] = root ; //setting pointer of child[0] to root
n -> child[1] = c ;
root = n ;
}
}
int btree :: setValue ( string val, btnode *n, string *p, btnode **ch ) //returns 1 or 0 to set flag
{
int key ;
if ( n == NULL )
{
*p = val ;
*ch = NULL ;
return 1 ; //if root is NULL 1 is returned to flag and node is created
}
else
{
if ( searchNode ( val, n, &key ) ) //checks if the value has already been entered
cout << endl << "Key value already exists." << endl ;
if ( setValue ( val, n -> child[key], p, ch ) )
{
if ( n -> count < MAX ) //if the node is less than MAX order the node is filled
{
fillNode ( *p, *ch, n, key ) ;
return 0 ; //value is returned as 0 to flag
}
else //if the MAX for node is met split
{
split ( *p, *ch, n, key, p, ch ) ;
return 1 ; //after split 1 is returned to flag to set node value
}
}
return 0 ;
}
}
void btree :: fillNode ( string val, btnode *c, btnode *n, int k ) //function to fill the node
{
int i ;
for ( i = n -> count ; i > k ; i-- ) //first node count is = to 1, k=0
{
n -> value[i + 1] = n -> value[i] ;
n -> child[i + 1] = n -> child[i] ;
}
n -> value[k + 1] = val ; //assigns string to location in node
n -> child[k + 1] = c ; //assigns pointer to child
n -> count++ ; //increments node count by one
}
void btree :: split ( string val, btnode *c, btnode *n,
int k, string *y, btnode **newnode )
{
int i, mid ;
cout<<"In split function k is :"<<k;
if ( k <= MIN )
mid = MIN ; //Min is defined as 2, the minimum number in a node
else
mid = MIN + 1 ; //k passing as 3 or 4 will make the midpoint 3
*newnode = new btnode ;
for ( i = mid + 1 ; i <= MAX ; i++ )
{
( *newnode ) -> value[i - mid] = n -> value[i] ; //new node value is placed at i - mid point setting it as first position in split node
( *newnode ) -> child[i - mid] = n -> child[i] ;
}
( *newnode ) -> count = MAX - mid ;
n -> count = mid ;
if ( k <= MIN )
fillNode ( val, c, n, k ) ;
else
fillNode ( val, c, *newnode, k - mid ) ; //fillNode is called and *newnode
*y = n -> value[n -> count] ; //mid point moves up to root node
( *newnode ) -> child[0] = n -> child[n -> count] ;
n -> count-- ;
}
void btree :: show( )
{
display ( root ) ;
}
void btree :: display ( btnode *root)
{
int i=0;
if ( root != NULL )
{
for ( i = 0 ; i < root -> count ; i++ )
{
cout<< root->value[i] ;
display ( root -> child[i] ) ;
}
display ( root-> child[i] ) ;
//cout<< root->value[i] ;
}
}
int main( )
{
btree b ;
int choice;
string key;
string t = "temp"; //to run through height function.
do{
cout<<"\n\n\tSELECT YOUR CHOICE\n\n1. insert\n2. search\n3. display\n4. height\n\n5. EXIT\n\n\n=";
cin>>choice;
switch(choice)
{
case 1:cout<<"\n\nEnter the string to be inserted:";
cin>>key;
b.insert(key);
break;
case 2:cout<<"\n\nEnter search:";
cin>>key;
// b.search(key);
break;
case 3:
cout<<"could not get to print A-Z?!." <<endl;
b.show();
cout<<"\n";
break;
case 4:
//b.height(t);
cout<<"\n";
break;
case 5:break;
default:cout<<"\nINVALID ENTRY";
break;};
}while(choice!=5);
return 0;
}
答案 0 :(得分：0)
void btree :: display ( btnode *root)
{
int i=0;
if ( root != NULL )
{
for ( i = 0 ; i < root -> count ; i++ )
{
cout<< root->value[i] ;
display ( root -> child[i] ) ;
}
到目前为止一切顺利。
display ( root-> child[i] ) ;
//cout<< root->value[i] ;
删除它。它再次显示root-＆gt; child [0]。你已经做到了。
}
}
答案 1 :(得分：0)
我调试代码的方式是（a）使其成为非交互式的，这样我就可以轻松地运行测试，（b）添加打印功能和语句。我从main()中删除了“用户界面”代码，并将其替换为硬编码的内容。
您的部分问题是insert()功能;它可能不会做你认为它做的事情。特别是，它将空树中的第一个值放入value[1]，而不是value[0]。我围绕这个问题编写了代码;在您需要拆分节点之前，它会有效。那时，它似乎丢失了一些数据。
玩得开心。
您应该将传递的字符串视为引用而不是值;我已经修复了一些，但绝不是所有这些。我找不到你需要的地方<stdlib.h>;我确实添加了<cassert>和一些断言，但我没有得到断言。
#include <cassert>
#include <iostream>
#include <string>
using namespace std;
const int MAX = 4;
const int MIN = 2;
struct btnode
{
int count;
string value[MAX + 1];
btnode *child[MAX + 1];
void dump(ostream &out, const string &tag);
};
void btnode::dump(ostream &out, const string &tag)
{
out << "-->> " << tag << ":\n";
out << "Count: " << count << "\n";
assert(value[0] == "");
for (int i = 1; i <= count; i++)
out << "Value " << i << " = <<" << value[i] << ">>\n";
out << "<<-- " << tag << "\n";
}
class btree
{
private:
btnode *root;
public:
btree() : root(0) {}
void insert(const string &val);
int setValue(const string &val, btnode *n, string *p, btnode **c);
void fillNode(string val, btnode *c, btnode *n, int k);
void split(string val, btnode *c, btnode *n, int k, string *y, btnode **newnode);
void show();
int searchPos(string key,string *key_arr,int n);
static void display(btnode *root);
static int searchNode(const string &val, btnode *n, int *pos);
};
int btree::searchNode(const string &val, btnode *n, int *pos)
{
if (val < n->value[1])
{
*pos = 0;
return 0;
}
else
{
*pos = n->count;
while ((val < n->value[*pos]) && *pos > 1)
(*pos)--;
if (val == n->value[*pos])
{
for(int j =0; j <= n->count; j++)
{
cout << n->value[j] << endl;
}
return 1;
}
else
return 0;
}
}
void btree::insert(const string &val)
{
cout << "-->> btree::insert('" << val << "')\n";
string in = "";
btnode *c = 0;
int flag = setValue(val, root, &in, &c);
cout << "setValue set flag = " << flag << "\n";
if (flag)
{
cout << "Creating new node\n";
btnode *n = new btnode;
assert(n != 0);
n->count = 1;
n->value[0] = "";
n->value[1] = in;
n->child[0] = root;
n->child[1] = c;
n->dump(cout, "New node");
root = n;
this->show();
}
cout << "<<-- btree::insert()\n";
}
int btree::setValue(const string &val, btnode *n, string *p, btnode **ch)
{
cout << "-->> setValue: <<" << val << ">>\n";
if (n == NULL)
{
*p = val;
*ch = NULL;
cout << "<<-- setValue: 1A\n";
return 1;
}
else
{
int key;
if (searchNode(val, n, &key))
cout << endl << "Key value already exists." << endl;
if (setValue(val, n->child[key], p, ch))
{
if (n->count < MAX)
{
fillNode(*p, *ch, n, key);
cout << "<<-- setValue: 0A\n";
return 0;
}
else
{
split(*p, *ch, n, key, p, ch);
cout << "<<-- setValue: 1B\n";
return 1;
}
}
cout << "<<-- setValue: 0B\n";
return 0;
}
}
void btree::fillNode(string val, btnode *c, btnode *n, int k)
{
for (int i = n->count; i > k; i--)
{
n->value[i + 1] = n->value[i];
n->child[i + 1] = n->child[i];
}
n->value[k + 1] = val;
n->child[k + 1] = c;
n->count++;
}
void btree::split(string val, btnode *c, btnode *n,
int k, string *y, btnode **newnode)
{
int i, mid;
cout << "In split function k is: " << k << "\n";
if (k <= MIN)
mid = MIN;
else
mid = MIN + 1;
*newnode = new btnode;
for (i = mid + 1; i <= MAX; i++)
{
(*newnode)->value[i - mid] = n->value[i];
(*newnode)->child[i - mid] = n->child[i];
}
(*newnode)->count = MAX - mid;
n->count = mid;
if (k <= MIN)
fillNode(val, c, n, k);
else
fillNode(val, c, *newnode, k - mid);
*y = n->value[n->count];
(*newnode)->child[0] = n->child[n->count];
n->count--;
}
void btree::show()
{
cout << "-->> show():\n";
display(root);
cout << "<<-- show()\n";
}
void btree::display(btnode *root)
{
if (root != NULL)
{
cout << "Root is not null\n";
int i;
for (i = 1; i <= root->count; i++)
{
cout << "Value " << i << " = <<" << root->value[i] << ">>\n";
if (root->child[i-1])
display(root->child[i-1]);
}
if (root->child[i])
display(root->child[i]);
}
else
cout << "Root is null\n";
}
int main()
{
btree b;
string key = "amaranthine";
b.insert(key);
b.show();
key = "absinthe";
b.insert(key);
b.show();
key = "amazonia";
b.insert(key);
b.show();
key = "zululand";
b.insert(key);
b.show();
key = "asbestos";
b.insert(key);
b.show();
return 0;
}
-->> btree::insert('amaranthine')
-->> setValue: <<amaranthine>>
<<-- setValue: 1A
setValue set flag = 1
Creating new node
-->> New node:
Count: 1
Value 1 = <<amaranthine>>
<<-- New node
-->> show():
Root is not null
Value 1 = <<amaranthine>>
<<-- show()
<<-- btree::insert()
-->> show():
Root is not null
Value 1 = <<amaranthine>>
<<-- show()
-->> btree::insert('absinthe')
-->> setValue: <<absinthe>>
-->> setValue: <<absinthe>>
<<-- setValue: 1A
<<-- setValue: 0A
setValue set flag = 0
<<-- btree::insert()
-->> show():
Root is not null
Value 1 = <<absinthe>>
Value 2 = <<amaranthine>>
<<-- show()
-->> btree::insert('amazonia')
-->> setValue: <<amazonia>>
-->> setValue: <<amazonia>>
<<-- setValue: 1A
<<-- setValue: 0A
setValue set flag = 0
<<-- btree::insert()
-->> show():
Root is not null
Value 1 = <<absinthe>>
Value 2 = <<amaranthine>>
Value 3 = <<amazonia>>
<<-- show()
-->> btree::insert('zululand')
-->> setValue: <<zululand>>
-->> setValue: <<zululand>>
<<-- setValue: 1A
<<-- setValue: 0A
setValue set flag = 0
<<-- btree::insert()
-->> show():
Root is not null
Value 1 = <<absinthe>>
Value 2 = <<amaranthine>>
Value 3 = <<amazonia>>
Value 4 = <<zululand>>
<<-- show()
-->> btree::insert('asbestos')
-->> setValue: <<asbestos>>
-->> setValue: <<asbestos>>
<<-- setValue: 1A
In split function k is: 3
<<-- setValue: 1B
setValue set flag = 1
Creating new node
-->> New node:
Count: 1
Value 1 = <<amazonia>>
<<-- New node
-->> show():
Root is not null
Value 1 = <<amazonia>>
Root is not null
Value 1 = <<absinthe>>
Value 2 = <<amaranthine>>
<<-- show()
<<-- btree::insert()
-->> show():
Root is not null
Value 1 = <<amazonia>>
Root is not null
Value 1 = <<absinthe>>
Value 2 = <<amaranthine>>
<<-- show()