private AsciiNode BuildAsciiTreeRecursive(TreeNode t)
{
if (t == null)
{
return(null);
}
AsciiNode node = new AsciiNode();
node.left = BuildAsciiTreeRecursive(t.left);
node.right = BuildAsciiTreeRecursive(t.right);
if (node.left != null)
{
node.left.parentDir = -1;
}
if (node.right != null)
{
node.right.parentDir = 1;
}
node.label = t.val.ToString();
return(node);
}
//This function prints the given level of the given tree, assuming
//that the node has the given x cordinate.
void PrintLevel(AsciiNode node, int x, int level)
{
if (node == null)
{
return;
}
int isleft = (node.parentDir == -1) ? 1 : 0;
if (level == 0)
{
int i = 0;
for (; i < (x - m_printNext - ((node.label.Length - isleft) / 2)); i++)
{
Console.Write(" ");
}
m_printNext += i;
Console.Write(node.label);
m_printNext += node.label.Length;
}
else if (node.edgeLength >= level)
{
if (node.left != null)
{
int i = 0;
for (; i < (x - m_printNext - (level)); i++)
{
Console.Write(" ");
}
m_printNext += i;
Console.Write("/");
m_printNext++;
}
if (node.right != null)
{
int i = 0;
for (; i < (x - m_printNext + (level)); i++)
{
Console.Write(" ");
}
m_printNext += i;
Console.Write("\\");
m_printNext++;
}
}
else
{
PrintLevel(node.left,
x - node.edgeLength - 1,
level - node.edgeLength - 1);
PrintLevel(node.right,
x + node.edgeLength + 1,
level - node.edgeLength - 1);
}
}
//Copy the tree into the ascii node structre
AsciiNode BuildAsciiTree(TreeNode t)
{
if (t == null)
{
return(null);
}
AsciiNode node = BuildAsciiTreeRecursive(t);
node.parentDir = 0;
return(node);
}
void ComputeRProfile(AsciiNode node, int x, int y)
{
if (node == null)
{
return;
}
int notleft = (node.parentDir != -1) ? 1 : 0;
m_rProfile[y] = Math.Max(m_rProfile[y], x + ((node.label.Length - notleft) / 2));
if (node.right != null)
{
for (int i = 1; i <= node.edgeLength && y + i < MAX_HEIGHT; i++)
{
m_rProfile[y + i] = Math.Max(m_rProfile[y + i], x + i);
}
}
ComputeRProfile(node.left, x - node.edgeLength - 1, y + node.edgeLength + 1);
ComputeRProfile(node.right, x + node.edgeLength + 1, y + node.edgeLength + 1);
}
//prints ascii tree for given Tree structure
public void PrintAsciiTree(TreeNode t)
{
if (t == null)
{
return;
}
AsciiNode proot = BuildAsciiTree(t);
ComputeEdgeLengths(proot);
for (int i = 0; i < proot.height && i < MAX_HEIGHT; i++)
{
m_lProfile[i] = INFINITY_NUM;
}
ComputeLProfile(proot, 0, 0);
int xMin = 0;
for (int i = 0; i < proot.height && i < MAX_HEIGHT; i++)
{
xMin = Math.Min(xMin, m_lProfile[i]);
}
for (int i = 0; i < proot.height; i++)
{
m_printNext = 0;
PrintLevel(proot, -xMin, i);
Console.Write("\n");
}
if (proot.height >= MAX_HEIGHT)
{
Console.Write("(This tree is taller than %d, and may be drawn incorrectly.)\n", MAX_HEIGHT);
}
}
//This function fills in the edgeLength and
//height fields of the specified tree
void ComputeEdgeLengths(AsciiNode node)
{
if (node == null)
{
return;
}
ComputeEdgeLengths(node.left);
ComputeEdgeLengths(node.right);
/* first fill in the edgeLength of node */
if (node.right == null && node.left == null)
{
node.edgeLength = 0;
}
else
{
int hmin = 0;
if (node.left != null)
{
for (int i = 0; i < node.left.height && i < MAX_HEIGHT; i++)
{
m_rProfile[i] = -INFINITY_NUM;
}
ComputeRProfile(node.left, 0, 0);
hmin = node.left.height;
}
else
{
hmin = 0;
}
if (node.right != null)
{
for (int i = 0; i < node.right.height && i < MAX_HEIGHT; i++)
{
m_lProfile[i] = INFINITY_NUM;
}
ComputeLProfile(node.right, 0, 0);
hmin = Math.Min(node.right.height, hmin);
}
else
{
hmin = 0;
}
int delta = 4;
for (int i = 0; i < hmin; i++)
{
delta = Math.Max(delta, GAP + 1 + m_rProfile[i] - m_lProfile[i]);
}
//If the node has two children of height 1, then we allow the
//two leaves to be within 1, instead of 2
if (((node.left != null && node.left.height == 1) ||
(node.right != null && node.right.height == 1)) && delta > 4)
{
delta--;
}
node.edgeLength = ((delta + 1) / 2) - 1;
}
//now fill in the height of node
int h = 1;
if (node.left != null)
{
h = Math.Max(node.left.height + node.edgeLength + 1, h);
}
if (node.right != null)
{
h = Math.Max(node.right.height + node.edgeLength + 1, h);
}
node.height = h;
}
