Binary Search Tree can't delete the root - c

Question

Everything is working fine in this function, but the problem is that I can't delete the root, I couldn't figure out what's the bug here.I've traced the "else part" it works fine until the return, it returns the old value I don't know why. Plz Help!
node *removeNode(node *Root, int key) {
node *tmp = new node;
if(key > Root->value)
Root->right = removeNode(Root->right,key);
else if(key < Root->value)
Root->left = removeNode(Root->left, key);
else if(Root->left != NULL && Root->right != NULL) {
node *minNode = findNode(Root->right);
Root->value = minNode->value;
Root->right = removeNode(Root->right,Root->value);
}
else {
tmp = Root;
if(Root->left == NULL)
Root = Root->right;
else if(Root->right == NULL)
Root = Root->left;
delete tmp;
}
return Root;
}

Answer 1

Change
removeNode(Root, key);
To
Root = removeNode(Root, key);
Root wasn't modify by removeNode because you pass a copy of the variable.

Answer 2

Using this style, where the result is the new tree, never forget to update the root:
Root = removeNode(Root, key);
Futhermore an empty tree must be tested for (Root == NULL)
node *removeNode(node *Root, int key) {
if(Root == NULL) // Or if(!Root) return Root;
return NULL;
if(key > Root->value)
Root->right = removeNode(Root->right,key);
else if(key < Root->value)
Root->left = removeNode(Root->left, key);
else if(Root->left != NULL && Root->right != NULL) {
node *minNode = findNode(Root->right); // Left most leaf
Root->value = minNode->value;
Root->right = removeNode(Root->right,Root->value);
}
else {
node *found = Rppt;
if(Root->left == NULL)
Root = Root->right;
else if(Root->right == NULL)
Root = Root->left;
delete found;
}
return Root;
}
Alternative style: using variable aliases
removeNode(&Root, key);
void removeNode(node **ptr_var, int key) {
node *ptr = *ptr_var;
if (!ptr)
return;
if (key > ptr->value)
removeNode(&ptr->right,key);
else if(key < ptr->value)
removeNode(&ptr->left, key);
else if(ptr->left && ptr->right) {
node **minNode = &ptr->right;
while (*minNode) {
minNode = &(*minNode)->left;
}
ptr->value = (*minNode)->value;
delete *minNode;
*minNode = NULL;
}
else {
if(! ptr->left)
*ptr_var = ptr->right;
else if(!ptr->right)
*ptr_var = ptr->left;
delete ptr;
}
}