我真的坚持如何在C ++中实现avltree的删除方法。 我不确定从哪里开始。我有方法来查找节点,旋转方法和插入工作,但实际上不确定如何启动此删除方法。我知道这是模糊的,网上有资源,但我不太清楚。有人可以解释一下这个过程吗?
如果您想查看任何代码,请询问:)
非常感谢任何和所有建议。 非常感谢提前!
-----编辑-----
查找节点方法:
Node* AVLtree::findNode(string cityID){
Node *thisNode = this->rootNode;
while(thisNode!=0){
int location = thisNode->getCity()->getName().compare(cityID);
if(location==0){return thisNode;
}else if(location<0){//cout<<"NODE: " << thisNode->getCity()->getName()<<endl;
thisNode = thisNode->getChildR();
}else{thisNode = thisNode->getChildL();}
}
return thisNode;
}
向左旋转:
Node* AVLtree::rotateLeft(Node* node){
Node* tempParent= node->getParent();
Node* tempNode = node->getChildL();
node->setChildL(tempNode->getChildR());
tempNode->setChildR(node);
if(tempParent==0){tempNode->removeParent();this->rootNode=tempNode;tempNode->getNewHeight();}
else{tempParent->setChildR(tempNode);
}
return tempNode;
}
向右旋转:
Node* AVLtree::rotateRight(Node* node){
Node* tempParent = node->getParent();
Node* tempNode = node->getChildR();
node->setChildR(tempNode->getChildL());
tempNode->setChildL(node);
if(tempParent==0){tempNode->removeParent();this->rootNode=tempNode;tempNode->getNewHeight();}
else{tempParent->setChildR(tempNode);}
return tempNode;
}
双重旋转,用于插入不平衡节点的右子节点的左子树时:
Node* AVLtree::rotateTwoRights(Node* node){
node = rotateLeft(node->getChildR());
node = rotateRight(node->getParent());
return node;
}
右,左条件的双重旋转:
Node* AVLtree::rotateTwoLefts(Node* node){
node = rotateRight(node->getChildL());
node = rotateLeft(node->getParent());
return node;
}
插入方法:
Node* AVLtree::insertNode(Node* parent, Node* node, City *city, int side){
if(node == 0){
if(side==0){
node = parent->setChildL(new Node(city));
}else if(side==1){
node = parent->setChildR(new Node(city));
}
}else if(node->getCity()->getName().compare(city->getName())<0){ //Right case
parent = node;
node = insertNode(parent, node->getChildR(), city, 1);
parent->getNewHeight();
if(parent->getBalance()==2){
if(parent->getChildR()->getCity()->getName().compare(city->getName())<0){
node = rotateRight(parent);
}else{
node = rotateTwoRights(parent);
}
}
}else if(node->getCity()->getName().compare(city->getName())>0){ //Left case
parent = node;
node = insertNode(parent, node->getChildL(), city, 0);
parent->getNewHeight();
if(parent->getBalance()==-2){
if(parent->getChildL()->getCity()->getName().compare(city->getName())>0){
node = rotateLeft(parent);
}else{
node = rotateTwoLefts(parent);
}
}
}else{
node=0;
}
return node;
}