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Boost-Commit : |
From: chintanraoh_at_[hidden]
Date: 2008-08-30 11:35:12
Author: chintanraoh
Date: 2008-08-30 11:35:11 EDT (Sat, 30 Aug 2008)
New Revision: 48473
URL: http://svn.boost.org/trac/boost/changeset/48473
Log:
moved size's body on to details
Text files modified:
sandbox/SOC/2008/digital_searching/dsearch/boost/dsearch/patricia.hpp | 1188 ---------------------------------------
1 files changed, 3 insertions(+), 1185 deletions(-)
Modified: sandbox/SOC/2008/digital_searching/dsearch/boost/dsearch/patricia.hpp
==============================================================================
--- sandbox/SOC/2008/digital_searching/dsearch/boost/dsearch/patricia.hpp (original)
+++ sandbox/SOC/2008/digital_searching/dsearch/boost/dsearch/patricia.hpp 2008-08-30 11:35:11 EDT (Sat, 30 Aug 2008)
@@ -415,44 +415,7 @@
*/
void clear()
{
- patricia_node *cur,*next;
- if(root==0) return;
- cur=root;
- root=0;
- while(true)
- {
- //*try going left if cur->left==0 try going right
- next=cur->left?cur->left:cur->right;
-
- if(next==0)
- {
- //*if cur->right is also 0 ==> next is 0.
- //*deallocate the node
- next=cur->par;
- deallocate_node(cur);
- if(next==0) return;
- //*adjust the parent pointer ->left or pp-> right to 0
- if(next->left==cur)
- next->left=0;
- else
- next->right=0;
- cur=next;
- }
- else
- if( next->par!=cur )
- {
- //*entered an uplink. so mark the thing as zero.
- if(cur->left==next)
- cur->left=0;
- else
- cur->right=0;
- }
- else
- {
- //*move forward to next
- cur=next;
- }
- }
+ pat_clear();
}
/// to find the no of values hashed into the array
@@ -460,46 +423,7 @@
*/
std::size_t size() const
{
- patricia_node *cur,*prev;
- std::size_t ret_size=0;
-
- prev=cur=root;
- while(cur)
- {
- if(cur->left==prev && cur->left->par==cur)
- {
- //*coming up from the left.
- prev=cur;
- //*try go right other wise got to the parent
- cur=(cur->right && cur->right->par==cur)?cur->right:cur->par;
- }
- else
- if(cur->right==prev && cur->right->par==cur)
- {
- //*coming up from the right
- //*goto the parent
- prev=cur;
- cur=cur->par;
- }
- else
- {
- //*going into a new node so increment size
- ret_size++;
- #ifdef PAT_DEBUG
- std::cout<<cur->value.first<<std::endl;
- #endif
- prev=cur;
-
- //*goto left otherwise goto right other go up.
- cur=(cur->left && cur->left->par==cur)? cur->left
- : ( (cur->right && cur->right->par==cur)? cur->right
- : cur->par );
- }
- //std::cout<<((prev->left==cur)?"GOING LEFT":(prev->right==cur)?
- //"GOING RIGHT":"GOING UP")<<std::endl;
- assert(ret_size!=10);
- }
- return ret_size;
+ return pat_size();
}
/// class destructor
@@ -510,1114 +434,8 @@
private:
- ///Has a pair of node pointers. usually has firt element as node found
- ///and second element as the node from which the upward edge goes.
- typedef std::pair<patricia_node*,patricia_node*> node_pair_type;
+ #include<boost/dsearch/details/patricia_details.hpp>
- ///find element points to point at which the bits become uncommon between two keys
- ///and second element as uncommon bit.
- ///second element=2 if two strings are equal.
- typedef std::pair<std::size_t,int> common_type;
-
- ///gets node pair b/w which a key is to inserted also returns a pair of index and bit value of the key at that index
- ///to get the pair of node between which a a node is to inserted
- ///this is for random access iterator.
- /**
- \returns std::pair< node_pair, common_type>. node_pair, ie pair of node between which the new node is to be inserted
- node_pair::second is the expected child of new node
- node_pair::first is the current parent of expected child.
- \param key is key to be inserted.
- */
- inline std::pair< node_pair_type, common_type>
- get_insert_pair(const key_type &key,rand_tag) const
- {
- patricia_node *cur=root,*next=root;
- std::size_t pos=0;
- common_type common;
- node_pair_type node_pair;
- const std::size_t key_size=Key_traits::size(key);
- key_iterator it=Key_traits::begin(key);
-
- //*get the insert pair for the key.
- node_pair=find_node_prev(root,key,iterator_cat(),key_size);
-
- next=node_pair.first;
- common=get_common_bits(key,next->value.first );
-
- //*if everything is common return the data type
- if ( common.second==2 )
- return std::make_pair(node_pair, common);
-
- //*else search for the key again
- next=cur=root;
- while (next->index < common.first) {
- cur=next;
- pos= cur->index / (bit_width + 1);
- //if ( pos >= key_size ) break;
- next=get_nth_bit ( Key_traits::get_element(it + pos), cur->index % (bit_width + 1) )?
- cur->right: cur->left;
- //*is its an upward link break.
- if(cur->index >= next->index) break;
- }
-
- //*return the node pair along with common pair.
- return std::make_pair(std::make_pair(next,cur), common);
- }
-
- ///gets node pair b/w which a key is to inserted also returns a pair of index and bit value of the key at that index
- ///to get the pair of node between which a a node is to inserted
- ///This uses forward iteration only
- /**
- \returns std::pair< node_pair, common_type>. node_pair, ie pair of node between which the new node is to be inserted
- node_pair::second is the expected child of new node
- node_pair::first is the current parent of expected child.
- \param key is key to be inserted.
- */
- template<class T>
- inline std::pair< node_pair_type, common_type>
- get_insert_pair (const key_type &key,T) const
- {
- key_iterator it,end_it;
- key_element_type temp_element;
- patricia_node *cur=root,*next=root;
- std::size_t pos=0;
- node_pair_type node_pair;
- common_type common;
-
- it=Key_traits::begin(key);
- end_it=Key_traits::end(key);
-
- //*get the node pair between which the key is supposed to be inserted
- node_pair=find_node_prev(root,key,T());
- next=node_pair.first;
- cur =node_pair.second;
- common=get_common_bits(key,next->value.first);
-
- //*key already exists
- if(common.second==2)
- return std::make_pair(std::make_pair(next,cur),common);
-
-
- //*find the correct parent and child in between which this node needs to be added.
- //*find until the index
- //*note: parent can be equal to child
- //*cur=parent, next=child
- it=Key_traits::begin(key);
- cur=root;
- while(it!=end_it)
- {
- if ( (cur->index)%(bit_width+1)==0 )
- {
- //*simply got the right because. left not has a lesser length than the key.
- next=cur->right;
- }
- else
- {
- //*goto left or right appropriately
- temp_element=Key_traits::get_element(it);
- next=get_nth_bit(temp_element,(cur->index)%(bit_width+1))?
- cur->right:cur->left;
- }
-
- //*fortunately in this case; this should happen only when it==end_it occures.
- assert(next);
- if ( next->index+1 > common.first ) break; //insert at cur using next->value->first
- if ( next->index <= cur->index ) break;
-
- //*increment pos and it until the required pos matching index is reached
- while( pos < (next->index)/(bit_width+1) && it!=end_it )
- {
- ++pos;
- ++it;
- }
- cur=next;
- }
-
- return std::make_pair(std::make_pair(next,cur),common);
- }
-
- ///Insert new node
- /**
- \returns reference to data_type in the new node.
- \param key is key to be inserted.
- */
- template<class T>
- inline data_type &insert_new_node(const key_type &key,T)
- {
- key_iterator it,end_it;
- patricia_node *cur=root,*next=root,*temp_node,*old_root=0;
- std::pair< std::pair<patricia_node*,patricia_node*>,
- std::pair<std::size_t,int> > insert_pair;
-
- //std::cout<<"in random access"<<std::endl;
-
- std::pair<std::size_t,int> common;
-
- //std::cout<<"\nInserting \""<<key<<"\""<<std::endl;
-
- it=Key_traits::begin(key);
- end_it=Key_traits::end(key);
-
- //*do some jugglery to ensure that inserting "" first as root wont cause any problems
- //*move root to the right position while inserting the second
- //*that will take care of the assert(next) in find
- old_root=0;
- if(root!=0 && root->left==root)
- {
- if(it==end_it) return root->value.second; //if one adds "" twice
- old_root=root;
- root=0;
- }
-
- if(root==0)
- {
- root=node_allocator.allocate(1);
- if(it!=end_it)
- {
- new(root) patricia_node( key, 0, old_root, root, 0 );
- if(old_root)
- {
- //*reassign the old root the position.
- old_root->par=root;
- }
- }
- else
- new(root) patricia_node( key, 0, root, 0, 0 );
- return root->value.second;
- }
-
- if(it==end_it)
- {
- //*"" inserted
-
- if(root->left==0)
- {
- root->left = node_allocator.allocate(1);
- new(root->left) patricia_node(key,0,root->left,0,root);
- }
- return root->left->value.second;
- }
-
- //*get the insert pair. the pair in between which the things should be inserted
- insert_pair=get_insert_pair(key,T());
-
- common=insert_pair.second;
- next=insert_pair.first.first;
- cur=insert_pair.first.second;
- //*if the key already exists return
- if(common.second==2)
- {
- #ifdef PAT_DEBUG
- std::cout<<"The key \""<<key<<"\" already exists"<<std::endl;
- #endif
- return next->value.second;
- }
-
- //*allocate new node
- temp_node=node_allocator.allocate(1);
-
- //*rewire the cur to temp_node
- if(cur->left==next)
- cur->left=temp_node;
- else
- if(cur->right==next)
- cur->right=temp_node;
- else
- assert(false);
-
-
- if(common.second)
- //*temp_node should point to inself at 1 ie right
- new (temp_node) patricia_node(key,common.first,next,temp_node,cur);
- else
- //*temp_node should point to inself at 0 ie right
- new (temp_node) patricia_node(key,common.first,temp_node,next,cur);
-
-
- assert(root->par==0);
-
- //*if its not an upward link adjust the next->par
- if(cur->index < next->index) next->par=temp_node;
-
- assert(root->par==0);
- return temp_node->value.second;
- }
-
- ///get nth element nth bit in the element
- /** \returns nth bit
- \param element whose nth bit is to be found
- \param n is the bit to be got
- */
- inline bool get_nth_bit(const key_element_type &element,const int &n) const
- {
- return n==0? 1 : ( ( element&(1<<(bit_width - n )) ) !=0 );
- }
-
- ///get the position upto which the bits are equal.
- /**
- \returns inclusive of end bit after each pos and the not(un) common bit in k1;
- \returns and the not common bit as two if both keys are equal.
- \param k1 is the first key
- \param k2 is the second key
- */
- inline std::pair<std::size_t,int> get_common_bits(const key_type &k1,const key_type &k2) const
- {
- key_iterator k1_it,k2_it,k1_end,k2_end;
- //std::cout<<"comparing "<<k1<<" and "<<k2<<std::endl;
- int uncommon_bit;
- key_element_type t1,t2;
- bool unequal=false;
- std::size_t pos=0;
-
- k1_it=k1.begin();
- k2_it=k2.begin();
- k1_end=k1.end();
- k2_end=k2.end();
-
- //*check until the chars are unequal and increment pos accordingly
- while(k1_it!=k1_end && k2_it!=k2_end )
- {
- if ( Key_traits::get_element(k1_it) != Key_traits::get_element(k2_it) )
- {
- unequal=true;
- break;
- }
- pos+=bit_width+1;
- ++k1_it;
- ++k2_it;
- }
-
- if(unequal)
- {
- //*find the unequal bit
- std::size_t bit_pos=0;
- t1=Key_traits::get_element(k1_it);
- t2=Key_traits::get_element(k2_it);
- key_element_type x=t1;
- while((t1)!=( t2))//possibly make this ( t1 & x) != ( t1 & x )
- {
- t1>>=1;
- t2>>=1;
- ++bit_pos;
- }
- uncommon_bit= ( ( x & (key_element_type(1)<<(bit_pos-1)) ) !=0);
- pos+=bit_width-bit_pos+1;
- //increment pos accordingly
- }
- else
- {
- //*assign uncommon_bit==2 if ( k1_it==k1_end && k2_it==k2_end )
- //*if k1_it==k1_end && k2_it!=k2_end assing 0
- //*otherwise 1
- uncommon_bit=(k1_it==k1_end)?((k2_it==k2_end)?2:0):1;
- }
-
- return std::make_pair<std::size_t,int>(pos,uncommon_bit);
- }
-
- ///find a node for the key.
- /**
- \returns the pointer to the "found" node
- \warning does not check whether the keys are actually equal.
- Will be needed to be done outside.
- \param cur is the node from which the search need to be made.
- \param key is the key to be searched
- */
- template<class T>
- inline patricia_node* find_node(const patricia_node* cur,const key_type &key,T) const
- {
- patricia_node *next;
- std::size_t pos=0;
- key_iterator it,end_it;
- key_element_type temp_element;
-
- it=Key_traits::begin(key);
- end_it=Key_traits::end(key);
-
- if(root==0) return 0;
- if(it==end_it)
- return root->left;
- //*adjust pos to the appropriate value
- while ( pos < (cur->index)/(bit_width+1) && it!=end_it )
- {
- ++pos;
- ++it;
- }
-
- while(it!=end_it) {
- if ( (cur->index)%(bit_width+1)==0 )
- {
- //*always go right as length of the key on right is lesser.
- next=cur->right;
- }
- else {
- //*go left or right appropriately.
- temp_element=Key_traits::get_element(it);
- //std::cout<<"getting "<<(cur->index)%(bit_width+1)<<"th bit of "<<temp_element<<std::endl;
- next=get_nth_bit ( temp_element , (cur->index)%(bit_width+1) ) ?
- cur->right : cur->left;
- }
- if(next==0) return next;
- //std::cout<<(cur->left==next?"going left":"going right")<<std::endl;
- //std::cout<<"next: "<<next->value.first<<std::endl;
-
- //*if we are heading toward the parent stop
- if ( next->index <= cur->index ) break;
-
- while ( pos < (next->index)/(bit_width+1) && it!=end_it ) {
- ++pos;
- ++it;
- }
- cur=next;
- }
-
- if ( it == end_it && pos==(cur->index)/(bit_width+1) ) {
- //*just make the required connection
- next=cur->left;
- }
- return next;
- }
-
- ///find a node for the key (over loaded for random access)
- /**
- \returns the pointer to the "found" node
- \warning does not check whether the keys are actually equal.
- Will be needed to be done outside.
- \param cur is the node from which the search need to be made.
- \param key is the key to be searched.
- \param key_size if the size of the key.
- */
- inline patricia_node* find_node(const patricia_node *cur, const key_type &key,rand_tag,std::size_t key_size=0) const
- {
- patricia_node *next=0;
- key_iterator it, end_it;
- it=Key_traits::begin(key);
- std::size_t pos=0;
- if(key_size==0)
- key_size=Key_traits::size(key);
-
- if ( root==0 ) return 0;
-
- while (true )
- {
- pos= cur->index / (bit_width + 1);
- //*make sure the key length is always lesser
- if ( pos >= key_size ) break;
- std::cout<<"getting "<<cur->index<<"th bit of "<<key<<std::endl;
- next=get_nth_bit ( Key_traits::get_element(it + pos), cur->index % (bit_width + 1) )?
- cur->right: cur->left;
- if(next==0) return 0;
- //*if we are heading toward the parent stop
- if(cur->index >= next->index) break;
- cur=next;
- }
-
- if (pos == key_size )
- {
- //*make the required correction if the add the last bit 0 to the node.
- next=cur->left;
- }
-
- return next;
- }
-
- ///find a node for the key and prev node also (over loaded for random access)
- /**
- \returns the pointer to the "found" node and node with upward link to found node
- as a pair.
- \warning does not check whether the keys are actually equal.
- Will be needed to be done outside.
- \param cur is the node from which the search need to be made.
- \param key is the key to be searched
- \param key_size is the size of key
- */
- inline node_pair_type
- find_node_prev(patricia_node *cur, const key_type &key, rand_tag,std::size_t key_size=0) const
- {
- patricia_node *next=0;
- key_iterator it, end_it;
- it=Key_traits::begin(key);
- std::size_t pos=0;
-
- if(key_size==0)
- key_size=Key_traits::size(key);
-
- if(cur==0) return std::make_pair<patricia_node*,patricia_node*>(0,0);
-
-
- if(it==end_it)
- {
- //*special cases for ""
- if ( cur==root || cur==root->left )
- return std::make_pair(root->left,root);
- else
- return std::make_pair(static_cast<patricia_node*>(0),static_cast<patricia_node*>(0));
- }
-
-
- //*refer find()
- while (true ) {
- pos= cur->index / (bit_width + 1);
- if ( pos >= key_size ) break;
- //std::cout<<Key_traits::get_element(it + pos)<<std::endl;
- next=get_nth_bit ( Key_traits::get_element(it + pos), cur->index % (bit_width + 1) )?
- cur->right: cur->left;
- //std::cout<<"In find: cur="<<cur->value.first
- //<<" going to next \""<<next->value.first<<"\""<<std::endl;
- if(next==0) return std::make_pair<patricia_node*,patricia_node*>(0,0);
- if(cur->index >= next->index) break;
- cur=next;
- }
-
- if(pos == key_size ) {
- next=cur->left;
- }
-
- return std::make_pair<patricia_node*,patricia_node*>(next,cur);
- }
-
- ///find a node for the key and prev node also
- /**
- \returns the pointer to the "found" node and node with upward link to found node
- as a pair.
- \warning does not check whether the keys are actually equal.
- Will be needed to be done outside.
- \param cur is the node from which the search need to be made.
- \param key is the key to be searche
- */
- template<class T>
- inline std::pair<patricia_node*,patricia_node*>
- find_node_prev(patricia_node *cur, const key_type &key, T ,std::size_t=std::size_t()) const
- {
- patricia_node *next;
- std::size_t pos=0;
- key_iterator it,end_it;
- key_element_type temp_element;
-
- it=Key_traits::begin(key);
- end_it=Key_traits::end(key);
-
- if(cur==0) return std::make_pair(cur,cur);
- if(it==end_it)
- {
- //*special cases for ""
- if ( cur==root || cur==root->left )
- return std::make_pair(root->left,root);
- else
- return std::make_pair(static_cast<patricia_node*>(0),static_cast<patricia_node*>(0));
- }
-
- //*adjust pos to match with cur->index
- while ( pos < (cur->index)/(bit_width+1) && it!=end_it ) {
- ++pos;
- ++it;
- }
-
- //*ref find :)
- while(it!=end_it) {
- if ( (cur->index)%(bit_width+1)==0 )
- {
- next=cur->right;
- }
- else {
- temp_element=Key_traits::get_element(it);
- std::cout<<temp_element<<std::endl;
- next=get_nth_bit ( temp_element , (cur->index)%(bit_width+1) ) ?
- cur->right : cur->left;
- }
- if(next==0) return std::make_pair(next,next);
-
- //std::cout<<next->value.first<<"<--"<<cur->value.first<<std::endl;
- if ( next->index <= cur->index ) { break;}
-
- while ( pos < (next->index)/(bit_width+1) && it!=end_it ) {
- ++pos;
- ++it;
- }
- cur=next;
- }
-
- if ( it == end_it && pos==(cur->index)/(bit_width+1) ) {
- next=cur->left;
- }
- return std::make_pair(next,cur);
- }
-
- ///erases the found node.
- /**
- \returns void
- \param found is the node to be erase.
- \param prev is the node with the uplink.
- */
- void erase(patricia_node*found,patricia_node *prev)
- {
- if(root==0 || found==0) return;
- #ifdef PAT_DEBUG
- std::cout<<"in erase: found "<<found->value.first<<" and prev "<<prev->value.first<<std::endl;
- #endif
- if ( found-> par == 0 ) {
- //*==> found=root node
- #ifdef PAT_DEBUG
- std::cout<<"par"<<std::endl;
- #endif
- assert(root==found);
-
- if( (found->right==0 || found->left==0) && found==prev){
- //*only root or only ""
- deallocate_node(found);
- root=0;
- return;
- }
- //std::cout<<"wrong place"<<std::endl;
-
- if(prev==found){
- //*also takes care of taking to "" to the root
- root=(found->right==found)?found->left:found->right;
- if(root) root->par=0;
- deallocate_node(found);
- return;
- }
- }
- else
- if ( found->right==0 || found->left==0 )
- prev=found;
- //* now prev contains the node from which found is wired with an uplink
- #ifdef PAT_DEBUG
- std::cout<<"here"<<std::endl;
- #endif
- //*if a node is looping to itself
- //*deleting the leaf node.
- //*this case for root node is handled before
- if ( prev == found ) {
-
-
- //*check how its liked to the par
- //*and found->par!=0 as root node has been handled before.
- if ( found->par->right == found )
- {
- //*rewire the parent.
- found->par->right = (found->right==found)?found->left:found->right;
- //*also take care rewiring the new childs parent
- if( found->par->right && found==found->par->right->par ) found->par->right->par=found->par;
- }
- else
- if ( found->par->left == found )
- {
- //*rewire the parent.
- found->par->left = (found->right==found)?found->left:found->right;
- //*also take care rewiring the new childs parent
- if( found->par->left && found==found->par->left->par ) found->par->left->par=found->par;
- }
- else
- assert(false);
- //std::cout<<"prev==found with key="<<key<<std::endl;
- if ( found->right==0 || found->left==0 )
- {
- //*Probably erasing "" for lets be extra careful
- //*check whether the par is as expected proper.
- assert(found->par==root);
- #ifdef PAT_DEBUG
- std::cout<<"\"\" node to be erased"<<std::endl;
- #endif
- }
- deallocate_node(found);
- return;
- }
-
- //*since we are moving prev to where found is we need to rewire the prev parents
- //*check how the prev->par is attached to prev
- if(prev->par->right==prev) {
- //*rewrite the prev->parent to the prev's other child
- prev->par->right=(prev->right==found)?prev->left:prev->right;
- //*if prev->right == prev or prev->left == prev there is a self loop so we need to take for it too.
- //*and not re-adjust par.
- if( prev->right!=prev && prev->left!=prev && prev->par->right ) prev->par->right->par=prev->par;
- }
- else {
- //std::cout<<"far away here"<<std::endl;
- //*rewrite the prev->parent to the prev's other child
- prev->par->left=(prev->right==found)?prev->left:prev->right;
- //*if prev->right == prev or prev->left == prev there is a self loop so we need to take for it too.
- //*and not re-adjust par.
- if( prev->right!=prev && prev->left!=prev && prev->par->left) prev->par->left->par=prev->par;
- }
-
- //*if we are deallocating the root
- if(found->par==0)
- root=prev;
- //*finally copy the pointers and index of found to prev node
- copy_node_ptr(prev,found);
- deallocate_node(found);
- }
-
- /// erase the node having key
- /**
- \returns void
- \param key is the key to be erase.
- */
- template<class T>
- void erase(const key_type& key,T)
- {
- patricia_node *cur,*found;
- std::pair<patricia_node*,patricia_node*> temp_pair,check_pair;
-
- if(root==0) return;
-
- assert(root->par==0);
-
- #ifdef PAT_DEBUG
- std::cout<< ((root->left!=0)?" \"\" exists":"\"\" does not exists")<<std::endl;
- #endif
-
- assert( (root->left!=0 && root->left!=root)? root->left->par==root: 1 );
-
- temp_pair=find_node_prev(root,key,T());
- found=temp_pair.first;
- cur=temp_pair.second;
- if(found==0) return;
-
- //check_pair=find_node_prev(root,key,rand_tag());
- //assert(check_pair==temp_pair);
-
- erase(found,cur);
- }
-
- ///deallocate a particular node. Used by erase.
- /**
- \returns void
- \param found is the pointer to the node to be erased
- */
- void inline deallocate_node(patricia_node *&found)
- {
- node_allocator.destroy(found);
- node_allocator.deallocate(found,1);
- }
-
-
- /// used by erase(key);
- ///copies pointers of two nodes. replacing the "found" node by "to" node.
- /**
- \returns void
- \param to is the node to replaced by.
- \param found is the node to replace.
- */
- void inline copy_node_ptr(patricia_node* to, patricia_node* found)
- {
- if(found->par!=0) {
- //*rewire found->par
- if(found->par->right==found)
- found->par->right=to;
- else
- found->par->left=to;
- }
- to->par=found->par;
-
- if(found->right!=found)
- //*if found is not connected to itself
- to->right=found->right;
- else
- to->right=to;
-
- if(found->left!=found)
- //*if found is not connected to itself
- to->left=found->left;
- else
- to->left=to;
-
- //*rewire the parents of left and right
- if ( found->left && found->left->par==found ) found->left->par=to;
- if ( found->right && found->right->par==found ) found->right->par=to;
-
- to->index=found->index;
- }
-
- ///finds the lower bound corresponding to the key.
- /**
- \returns the iterator pointing to the lower bound.
- if there is no lower bound return end()
- \param key is the key whose upper bound is to be found
- */
- template<class T>
- inline iterator lower_bound(const key_type &key,T)
- {
- typedef std::pair<patricia_node*,patricia_node*> node_pair_type;
- typedef std::pair<std::size_t, int> common_type;
-
- std::pair<node_pair_type,common_type> node_pair;
- common_type common;
- patricia_node* next,*cur;
- iterator it;
-
-
- if(root==0) return end();
- if ( Key_traits::begin(key)==Key_traits::end(key) )
- {
- //* Special case for ""
- if(root->left==0) return end();
- else
- return begin();
- }
-
- /// Check whether there keys other that "" at all.
- if(root->right==0)
- {
- //* Lowerbound has to be ""
- return begin();
- }
-
- /// Get pair where one needs to insert the node corresponding to the key
- /// this we "simulate" the insertion and check the element lesser that it.
- node_pair = get_insert_pair(key,T());
- next = node_pair.first.first;
- cur = node_pair.first.second;
- common = node_pair.second;
-
- switch(common.second)
- {
- case 2:
- //*case where key is found.
- return iterator(next,cur);
- case 0:
- //*case where next->value.key > key. this ensures that all the nodes in the
- //*subtree also greater
- return --iterator(next,cur);
- case 1:
- //*case where the lower bound is in the subtree of next.
- it=iterator(next,cur);
- //*we just move to the highest value in the subtree.
- it.to_right_most();
- return it;
- }
- assert(false);
- }
-
- ///finds the upper bound corresponding to the key.
- /**
- \returns the iterator pointing to the upperbound.
- if there is no upper bound return end()
- \param key is the key whose upper bound is to be found
- */
- template<class T>
- inline iterator upper_bound(const key_type &key,T)
- {
- typedef std::pair<patricia_node*,patricia_node*> node_pair_type;
- typedef std::pair<std::size_t, int> common_type;
-
- std::pair<node_pair_type,common_type> node_pair;
- common_type common;
- patricia_node* next,* cur;
- iterator it;
-
- if ( root==0 ) return end();
- if ( Key_traits::begin(key)==Key_traits::end(key) )
- return begin();
-
- //* Check whether there keys other that "" at all.
- if ( root->right==0 )
- {
- //*explicitly find the upper bound
- if(Key_traits::begin(key)!=Key_traits::end(key) )
- return end();
- else
- return begin();
- }
-
- node_pair=get_insert_pair(key,T());
- next=node_pair.first.first;
- cur =node_pair.first.second;
- common=node_pair.second;
- #ifdef PAT_DEBUG
- std::cout<<"Upper Bound:SECOND: "<<common.second<<std::endl;
- #endif
- switch ( common.second )
- {
- case 2:
- //*key aleardy exists
- return iterator(next,cur);
- case 1:
- //*upper bound is not in the subtree of next.its just greater than the subtree
- return ++iterator(next,cur);
- case 0:
- //*it is in the subtree
- it=iterator(next,cur);
- #ifdef PAT_DEBUG
- std::cout<<next->value.first<<"<-"<<cur->value.first<<std::endl;
- #endif
- //*go to the least element in the subtree.
- it.to_left_most();
- return it;
- }
- assert(false);
- }
-
- ///finds the iterator range corresponding to the prefix (overloaded for random access)
- /**
- \returns iterator range
- \param key is the key whose prefix range is to be found
- */
- std::pair<iterator,iterator> prefix_range(const key_type &key,rand_tag)
- {
- std::size_t pos=0;
- std::pair<patricia_node*,patricia_node*> node_pair;
- std::pair<std::size_t,int> common;
- const std::size_t key_size=Key_traits::size(key);
- patricia_node *cur=root,*next=root;
- key_iterator it=Key_traits::begin(key);
-
- if(root==0) return std::make_pair(end(),end());
-
- //*if its "" then entire patricia is needed
- if(Key_traits::begin(key)==Key_traits::end(key))
- return std::make_pair(begin(),end());
-
-
- //*now key!="" and there is no other key in the patricia
- //*so only option is end(),end()
- if(root->right==0) return std::make_pair(end(),end());
-
- //*find node in between which the node was supposed to be inserted
- node_pair=find_node_prev(root,key,iterator_cat(),key_size);
-
- next=node_pair.first;
- common=get_common_bits(key,next->value.first );
- if ( common.second==2 ) {
- common.second=0;
- //*if key is already found we will need to re adjust this thing
- //*the bit index to be searched for
- common.first=key_size*( bit_width + 1 );
- #ifdef PAT_DEBUG
- std::cout<<"FOUND"<<std::endl;
- #endif
- }
-
- //*if we did not find a key with entire string as prefix. then then
- //*then we will need to ditch the procedure here.
- if ( common.second!=0 || common.first % ( bit_width + 1 ) != 0)
- return std::make_pair(end(),end());
- #ifdef PAT_DEBUG
- std::cout<<"HERE with KEY="<<key<<std::endl;
- #endif
-
- //*we start searching for the until we get a key with index>common.first
- next=cur=root;
- while (next->index < common.first) {
- cur=next;
- pos= cur->index / (bit_width + 1);
- //if ( pos >= key_size ) break;
- next=get_nth_bit ( Key_traits::get_element(it + pos), cur->index % (bit_width + 1) )?
- cur->right: cur->left;
- if(cur->index >= next->index) break;
- }
-
-
- iterator right=iterator(next,cur);
- iterator left =iterator(next,cur);
-
- //*find the smallest in the subtree of next
- left.to_left_most();
-
- //*find one greater than greatest in the subtree of next.
- ++right;
- return std::make_pair(left,right);
- }
-
- ///finds the iterator range corresponding to the prefix (overloaded for random access)
- /**
- \returns iterator range
- \param key is the key whose prefix range is to be found
- */
- template<class T>
- std::pair<iterator,iterator> prefix_range(const key_type &key,T)
- {
- key_iterator it,end_it;
- key_element_type temp_element;
- patricia_node *cur=root,*next=root;
- std::size_t pos=0;
- std::pair<patricia_node*,patricia_node*> node_pair;
- std::pair<std::size_t,int> common;
- bool no_check=false;
-
- it=Key_traits::begin(key);
- end_it=Key_traits::end(key);
-
- //*if its "" then entire patricia is needed
- if(root==0) return std::make_pair(end(),end());
- if(Key_traits::begin(key)==Key_traits::end(key))
- return std::make_pair(begin(),end());
-
- //*if we did not find a key with entire string as prefix. then then
- //*then we will need to ditch the procedure here.
- if(root->right==0) return std::make_pair(end(),end());
-
- node_pair=find_node_prev(root,key,T());
-
- next=node_pair.first;
- assert(find_node_prev(root,key,iterator_cat()).first==next);
- cur =node_pair.second;
- assert(find_node_prev(root,key,iterator_cat()).second==cur);
- common=get_common_bits(key,next->value.first);
-
- if(common.second==2)
- {
- common.second=0;
- //*no_check will indicate whether or not to check for next->index+1 > common.first
- no_check=true;
- }
- if ( common.second!=0 || common.first % ( bit_width + 1 ) != 0)
- return std::make_pair(end(),end());
-
- //*we start searching for the until we get a key with index>common.first
- it=Key_traits::begin(key);
- cur=root;
- while(it!=end_it)
- {
- if ( (cur->index)%(bit_width+1)==0 )
- next=cur->right;
- else
- {
- temp_element=Key_traits::get_element(it);
- next=get_nth_bit(temp_element,(cur->index)%(bit_width+1))?
- cur->right:cur->left;
- }
-
- //*fortunately in this case; this should happen only when it==end_it occures.
- assert(next);
- if ( no_check || next->index+1 > common.first ) break; //insert at cur using next->value->first
- if ( next->index <= cur->index ) break;
-
- while( pos < (next->index)/(bit_width+1) && it!=end_it )
- {
- ++pos;
- ++it;
- }
- cur=next;
- }
- iterator right=iterator(next,cur);
- iterator left =iterator(next,cur);
-
- //*find the smallest in the subtree of next
- left.to_left_most();
-
- //*find one greater than greatest in the subtree of next.
- ++right;
- return std::make_pair(left,right);
- }
-
- ///used by copy_patricia
- ///find the ancestor node in this patricia corresponding to parent node in other patricia
- /**
- \returns pointer to the ancestor patricia which has corresponding incoming upward link
- \param this_cur is the node pointer whose upward link is to be found
- \param other_cur is the node pointer, of the other patricia, which has the upward link.
- \param par is the node in the other patricia which is the upward link.
- */
- patricia_node *copy_patricia_find_par(patricia_node* const &this_cur,
- const patricia_node* const &other_cur,const patricia_node * const &par)
- {
- patricia_node *cur=this_cur;
- const patricia_node* o_cur=other_cur;
- if(other_cur==0) return 0;
- while(o_cur!=par)
- {
- cur=cur->par;
- o_cur=o_cur->par;
- }
- return cur;
- }
-
- ///copy other patricia on to this patricia.
- /**
- \return void
- \param other_root is the pointer to the root of other patricia to be copied.
- */
- void copy_patricia(const patricia_node *other_root)
- {
- const patricia_node *const*other_cur,*other_temp,*other_prev;
-
- //*cur is the pointer to the edge.
- //*ie, most of the times, cur=&node->left or cur=&node->right
- patricia_node **cur,*prev;
-
- if(other_root==0)
- {
- this->root=0;
- return;
- }
-
- cur=&root;
- other_cur=&other_root;
- other_prev=0;
- prev=0;
- while(true)
- {
- //assert(prev!=other_root);
- //*if the current edge in other patricia does not point to
- //*null and is not the upward edge.
- if( (*other_cur) && (*other_cur)->par==other_prev)
- {
- //*allocate a node in the current of edge of this node.
- (*cur)=node_allocator.allocate(1);
-
- //*copy index, data_type and key_type.
- new(*cur) patricia_node(**other_cur);
- (*cur)->par = prev;
-
- //*get in to the next node and and move to the left edge.
- other_prev=*other_cur;
- other_cur=&(other_prev->left);
-
- //*do the same for the this patricia too.
- prev=*cur;
- cur=&(prev->left);
- //std::cout<<"copy:here1"<<std::endl;
- continue;
- }
- std::cout<<"copy:here2"<<std::endl;
-
- //*when we come here we know that the edge is iether null or point upwards
- //*copy_patricia_find_par returns null is edge points to null.
- //*otherwise it returns the corresponding parent
- (*cur)=copy_patricia_find_par(prev,other_prev,*other_cur);
-
- //*some random assert to check the pointers dont get interchaged by mistake
- assert((*cur)!=other_root);
-
- //*if the edge is the left is the left edge
- if((*other_cur)==other_prev->left)
- {
- //*move towards the right egde
- other_cur=&(other_prev->right);
- //assert(other_prev!=prev);
- cur=&(prev->right);
- }
- else
- {
- //*if already on the right edge one needs to move upward to traverse further.
- other_temp=other_prev->right;
- //*check whether we are on the right edge.
- while(other_temp==other_prev->right)
- {
- other_temp=other_prev;
- //*if right keep moving up
- other_prev=other_prev->par;
-
- //*do the same in other patricia too.
- prev=prev->par;
- if(other_prev==0)
- {
- //*Finished scanning through the entire patricia.
- //*now return.
- return;
- }
- }
-
- //*finally its not right any more. :)
- //*so adjust both edges towards the right
- other_cur=&other_prev->right;
- cur=&prev->right;
- }
- }
- }
};
///check the equality of the two patricia nodes
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