public void PrintTree(Node r) {
if(r==null) return;
Console.WriteLine("{0}, {1}",r.key,r.color);
if(r.left!=null) PrintTree(r.left);
if(r.right!=null) PrintTree(r.right);
}
public bool InsertNode() {
Node n=BuildNode();
if(n==null) return false;
if(root==null) {
root=n;
root.color="black";
return true;
}
//Rule 1: Every node has value (key) greater than left-child & less than the right-child value
// so traverse tree to find it's place
Node temp=root;
while((temp.left!=null) || (temp.right!=null)) {
if(n.key < temp.key) {
if(temp.left != null) {
temp=temp.left;
continue;
}
else {
temp.left=n;
n.parent=temp;
return true;
}
}
else if(n.key > temp.key){
if(temp.right != null) {
temp=temp.right;
continue;
}
else {
temp.right=n;
n.parent=temp;
return true;
}
}
}
if(n.key < temp.key)
temp.left=n;
else if(n.key > temp.key)
temp.right=n;
n.parent=temp;
// Adjust tree after insertion
AdjustTree(n);
return true;
}
public void SetNodeColor(Node n) {
//Rule 5. Red node which is not a leaf has black children(consecutive red nodes not allowed)
if(n.color=="red") { //set child color as black
if(n.left!=null) n.left.color="black";
if(n.right!=null) n.right.color="black";
}
if(n.left!=null) SetNodeColor(n.left);
if(n.right!=null) SetNodeColor(n.right);
}
public Node FindNode(Node r,int k) {
//Console.WriteLine("In FindNode()");
try {
if(k==r.key) return r;
else if(k<r.key) {
if(r.left!=null) return(FindNode(r.left,k));
else return null; // skip this node
}
else {
if(r.right!=null) return(FindNode(r.right,k));
else return null;
}
}catch(Exception e) {
Console.WriteLine("Exception caught in FindNode(): "+e);
return null;
}
}
public string WhichChild(Node n) {
if(n==root) return "none";
if(n==n.parent.left) return "left";
else return "right";
}
public void RotateTree(Node x) {
Node uncle=null;
Node sibling=null;
if(x.parent.color=="red") {
if(WhichChild(x.parent)=="left") // uncle is the right child
//if((x.parent).parent.right != null)
uncle=(x.parent).parent.right;
else if(WhichChild(x.parent)=="right") // uncle is the left child
//if((x.parent).parent.left != null)
uncle=(x.parent).parent.left;
if(WhichChild(x)=="left") // x is left child
//if(x.parent.right != null)
sibling=x.parent.right;
else //x is right child
//if(x.parent.left != null)
sibling=x.parent.left;
}
else return;
//Rotation Type 1 : x is red, p[x] is red and uncle=null, sibling=null
if((uncle==null)&&(sibling==null)) {
//Different orientation...Works!
if(WhichChild(x)!= WhichChild(x.parent)) {
int temp = x.key;
x.key=x.parent.key;
x.parent.key=temp;
// reverse orientations
if(WhichChild(x)=="left") {
x.parent.right=x;
x.parent.left=null;
}
else {
x.parent.left=x;
x.parent.right=null;
}
RotateTree(x);
}
// Same orientation..Works!
else {
if(x.parent.parent != root) {
if(WhichChild(x.parent.parent) == "left")
x.parent.parent.parent.left=x.parent;
else x.parent.parent.parent.right=x.parent;
}
else root=x.parent;
if(WhichChild(x)=="left") {
(x.parent).right=(x.parent).parent;
((x.parent).right).parent=x.parent;
/*if(WhichChild(x.parent) == "left") {
Console.WriteLine("ok");
x.parent.parent.left=null;
}
else { ((x.parent).right).right=null;}*/
x.parent.parent.left=null;
x.parent.right.color="red";
//Console.WriteLine("root {0},left {1}, right {2}, last row {3},{4},{5},{6}",root.key,root.left.key,root.right.key,root.left.left,root.left.right,root.right.left,root.right.right);
}
else {
x.parent.left=x.parent.parent;
x.parent.left.parent=x.parent;
if(WhichChild(x.parent) == "left") x.parent.left.left=null;
else x.parent.left.right=null;
x.parent.left.color="red";
}
x.parent.color="black";
}
} // end of Rotation Type 1
//Rotation Type 2: depending on uncle's color
else {
switch(uncle.color) {
case "red":
if(WhichChild(uncle)=="left") x.parent.parent.left.color="black"; //u[x] = black
else x.parent.parent.right.color="black";
x.parent.color="black"; //p[x] = black
x.parent.parent.color="red"; //p(p[x]) = red
break;
case "black":
if(WhichChild(x)=="right") {
x.parent.color="black";
x.parent.left.color="red";
}
else {
}
break;
default: break;
}
}
}
public void AdjustTree(Node x) {
//Rule 10: Readjustment of the tree is by rotation
RotateTree(x);
//Rule 3: Root is black
root.color="black";
//Rule 4: Leaf is red...automatically as we have all nodes as red to begin with
//Rule 5. Red node which is not a leaf has black children(consecutive red nodes not allowed)
//SetNodeColor(root);
}
public bool UniqueKey(Node r,int k) {
if(root==null) return true;
//Console.WriteLine("r.key={0} , k={1}",r.key, k);
if(k==r.key) return false;
else if(k<r.key){
if(r.left!=null) return(UniqueKey(r.left,k));
else { return true;}
}
else {
if(r.right!=null) return(UniqueKey(r.right,k));
else { return true;}
}
}
public Node BuildNode() {
Node temp;
try {
temp = new Node();
}catch(Exception e) {
Console.WriteLine("Caught: {0}",e);
return null;
}
int k = rand.Next(0,nodes);
bool result = UniqueKey(root,k);
while(result==false) {
k = rand.Next(0,nodes);
result=UniqueKey(root,k);
}
temp.key = k;
temp.color = "red"; //Rule 4: Leaf is red
try {
temp.array = new int[128]; // Just allocating array of small size nodes(due to bug#84431)
//temp.array = new int[k]; // Just allocating array of size of the key
}catch(Exception e) {
Console.WriteLine("Caught: {0}",e);
temp.array = new int[5];
}
//Console.WriteLine("inserted: {0}",temp.key);
return temp;
}