// Traverse the tree to check the levels of the tree T including node T itself
public int level(BiTree T)
{
if (T == null)
{
return(0);
}
else
{
if ((T.lchild != null) && (T.rchild != null))
{
int a = T.level(T.lchild);
int b = T.level(T.rchild);
return(1 + ((a > b) ? a : b));
}
else if (T.lchild != null)
{
return(T.level(T.lchild) + 1);
}
else if (T.rchild != null)
{
return(T.level(T.rchild) + 1);
}
else
{
return(1);
}
}
}
// Traverse the tree to check the number of nodes under the tree T including node T itself
public int NodeNum(BiTree T)
{
if (T == null)
{
return(0);
}
else
{
if ((T.lchild != null) && (T.rchild != null))
{
return(T.NodeNum(T.lchild) + T.NodeNum(T.rchild) + 1);
}
else if (T.lchild != null)
{
return(T.NodeNum(T.lchild) + 1);
}
else if (T.rchild != null)
{
return(T.NodeNum(T.rchild) + 1);
}
else
{
return(1);
}
}
}
//PreOrder traverse the tree and read all the integers into an IntArray
public bool PreOrder(BiTree T, IntArray s)
{
if (T == null)
{
return(false);
}
else
{
PreOrder(T.lchild, s);
s.Push(T.key); // store the integer into IntArray
PreOrder(T.rchild, s);
return(true);
}
}
//insert an integer x into Tree T, by returning the newly inserted Tree node
public BiTree Insert(BiTree T, int x)
{
if (T == null)
{
BiTree s = new BiTree(x);
T = s;
return(s);
}
else if (x == T.key)
{
return(T);
}
else if (x < T.key)
{
T.lchild = this.Insert(T.lchild, x);
return(T);
}
else
{
T.rchild = this.Insert(T.rchild, x);
return(T);
}
}
public BiTree(int x) // constructor
{
this.key = x;
this.lchild = null;
this.rchild = null;
}
static void Main(string[] args)
{
char[] delimiterChars = { ' ' }; // set up the dilimiter char array, which includes space
Console.WriteLine("Enter a collection of numbers in the range [0, 100], separated by spaces:");
string input = Console.ReadLine(); // read inputs from console
int[] array = null; // store input integer arrays
// Considering some error inputs like null or not an integer, write the console out
if (input == null)
{
Console.WriteLine("User input format is null!");
}
else
{
// do a split of string to get strings of integers
string[] words = input.Split(delimiterChars, System.StringSplitOptions.RemoveEmptyEntries);
if (words.Length == 0)
{
Console.WriteLine("User input length 0!"); // user enters 0 qualified string
}
else
{
array = new int[words.Length];
for (int i = 0; i < words.Length; i++)
{
if (Int32.TryParse(words[i], out array[i]))
{
Console.WriteLine(array[i]); // do parse to translate strings into integers
}
else
{
Console.WriteLine("User input not a number!");
}
}
}
}
// Next, We want to build our binary search Tree.
if (array == null)
{
Console.WriteLine("User input error!"); // no integer is entered
}
else
{
BiTree T = new BiTree(array[0]); // establish the binary search tree
for (int i = 1; i < array.Length; i++)
{
T.Insert(T, array[i]);
}
int count = T.NodeNum(T);
IntArray A = new IntArray(count); // read the integers from tree to a designed int array class IntArray
T.PreOrder(T, A);
string tmp = "Tree contents: "; // show the tree contents
//
for (int i = 0; i < A.cnt; i++)
{
tmp += A.arr[i] + " "; // combine the integers from int array into a string, tmp
}
// display all the required like contents, node number, levels ...
Console.WriteLine(tmp);
Console.WriteLine("Tree statistics:");
Console.WriteLine(" Number of nodes: {0}", count);
Console.WriteLine(" Number of levels: {0}", T.level(T));
Console.WriteLine(" Minimum number of levels that a tree with {0} nodes could have = {1}", count, Math.Ceiling(Math.Log((double)count + 1) / Math.Log(2)));
Console.WriteLine("Done!");
}
}