static void Main(string[] args)
{
Program p = new Program();
TreeNode node = new TreeNode(-1) { left = new TreeNode(-2), right = new TreeNode(-3) };
Console.WriteLine(p.serialize(node));
node = p.deserialize(p.serialize(node));
}
private TreeNode deserializeInternal(string data, int start, out int i)
{
TreeNode node = null;
int count = 0;
bool rightFlag = false;
bool neg = false;
i = start;
while (++i < data.Length)
{
if (data[i] == ')')
{
break;
}
else if (data[i] == ',')
{
if (node == null)
node = new TreeNode(neg ? -count : count);
else
rightFlag = true;
}
else if (data[i] == '(')
{
if (rightFlag)
node.right = deserializeInternal(data, i, out i);
else
node.left = deserializeInternal(data, i, out i);
}
else if (data[i] == '-')
{
neg = true;
}
else
{
int n = data[i] - '0';
count = 10 * count + n;
}
}
return node;
}
private void serializeInternal(StringBuilder sb, TreeNode root)
{
if (root == null)
return;
sb.Append('(');
sb.Append(root.val);
sb.Append(',');
serializeInternal(sb, root.left);
sb.Append(',');
serializeInternal(sb, root.right);
sb.Append(')');
}
// Encodes a tree to a single string.
public string serialize(TreeNode root)
{
StringBuilder sb = new StringBuilder();
serializeInternal(sb, root);
return sb.ToString();
}