binary search tree

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#include <iostream>
struct tnode {
int value;
tnode* left;
tnode* right;
tnode() {
left == NULL;
right == NULL;
}
};
tnode* search_bst(tnode* rootTree, int searcher) {
if (rootTree == NULL) {
return NULL;
} else if (rootTree->value > searcher) {
search_bst(rootTree->left, searcher);
} else if (rootTree->value < searcher) {
search_bst(rootTree->right, searcher);
} else if (rootTree->value == searcher) {
return rootTree;
}
}
void insertNode(tnode*& rootTree, tnode* newNode) {
if (rootTree == NULL) {
rootTree = newNode;
} else if (rootTree->value > newNode->value) {
insertNode(rootTree->left, newNode);
} else {
insertNode(rootTree->right, newNode);
}
}
void deleteNode(tnode*& rootTree, int key) {
// поиск удаленный узел
tnode* delNode = rootTree;
while (delNode->value != key) {
if (delNode->value < key) {
delNode = delNode->left;
} else if (delNode->value > key) {
delNode = delNode->right;
}
}
std::cout<<delNode->value;
// В случае, у удаленного узла иммет только одна потомка
if (delNode->left == NULL) {
delNode = delNode->right;
} else if (delNode->right == NULL) {
delNode = delNode->left;
} else {
tnode* leftOfDelNode = delNode->left;
// поиск the most right node of left tree, which root now is deleted node
while(leftOfDelNode->right != NULL) {
leftOfDelNode = leftOfDelNode->right;
}
delNode->value = leftOfDelNode->value;
deleteNode(rootTree, leftOfDelNode->value);
}
}
void visitTree(tnode* rootTree) {
if(rootTree == NULL) {
std::cout<<"NIL"<<std::endl;
} else {
std::cout<<rootTree->value<<" ";
visitTree(rootTree->left);
visitTree(rootTree->right);
}
}
int main() {
tnode* rootTree;
tnode* right;
tnode* left;
right = new tnode;
right->value = 12;
left = new tnode;
left->value = 8;
rootTree = new tnode;
rootTree->value = 10;
insertNode(rootTree, right);
insertNode(rootTree, left);
tnode* temp = search_bst(rootTree, 8);
std::cout<<temp->value;
deleteNode(rootTree, 8);
visitTree(rootTree);
delete right;
delete left;
delete rootTree;
return 0;
}