public static FrogNode CreateFrogNodeTree(int numberOfFrogs)
{
FrogNode root = new FrogNode(numberOfFrogs);
root = FrogNode.CreateFrogPossibilities(root);
return(root);
}
static void Main(string[] args)
{
FrogNode.DFS(0);
FrogNode.DFS(1);
FrogNode.DFS(2);
FrogNode.DFS(3);
FrogNode.DFS(4);
}
public override bool Equals(object obj)
{
if (!(obj is FrogNode))
{
return(false);
}
FrogNode node = obj as FrogNode;
for (int i = 0; i < Frogs.Count; i++)
{
if (Frogs[i] != node.Frogs[i])
{
return(false);
}
}
return(true);
}
static FrogNode CreateFrogPossibilities(FrogNode node)
{
if (node.ZeroPos - 1 >= 0 && node.Frogs[node.ZeroPos - 1] == '>')
{
FrogNode newNode = new FrogNode(node);
newNode.ZeroPos = node.ZeroPos - 1;
newNode.Frogs[node.ZeroPos] = '>';
newNode.Frogs[newNode.ZeroPos] = '_';
node.Nodes.Add(newNode);
}
if (node.ZeroPos - 2 >= 0 && node.Frogs[node.ZeroPos - 2] == '>')
{
FrogNode newNode = new FrogNode(node);
newNode.ZeroPos = node.ZeroPos - 2;
newNode.Frogs[node.ZeroPos] = '>';
newNode.Frogs[newNode.ZeroPos] = '_';
node.Nodes.Add(newNode);
}
if (node.ZeroPos + 1 < node.Frogs.Count && node.Frogs[node.ZeroPos + 1] == '<')
{
FrogNode newNode = new FrogNode(node);
newNode.ZeroPos = node.ZeroPos + 1;
newNode.Frogs[node.ZeroPos] = '<';
newNode.Frogs[newNode.ZeroPos] = '_';
node.Nodes.Add(newNode);
}
if (node.ZeroPos + 2 < node.Frogs.Count && node.Frogs[node.ZeroPos + 2] == '<')
{
FrogNode newNode = new FrogNode(node);
newNode.ZeroPos = node.ZeroPos + 2;
newNode.Frogs[node.ZeroPos] = '<';
newNode.Frogs[newNode.ZeroPos] = '_';
node.Nodes.Add(newNode);
}
foreach (FrogNode child in node.Nodes)
{
FrogNode.CreateFrogPossibilities(child);
}
return(node);
}
public static void DFS(int numberOfFrogs)
{
if (numberOfFrogs <= 0)
{
Console.WriteLine("No frogs to swap!");
return;
}
FrogNode root = FrogNode.CreateFrogNodeTree(numberOfFrogs);
FrogNode searched = new FrogNode(numberOfFrogs, '<', '>');
Stack <FrogNode> path = new Stack <FrogNode>();
List <FrogNode> visited = new List <FrogNode>();
path.Push(root);
while (path.Any())
{
FrogNode top = path.Peek();
if (top.Equals(searched))
{
FrogNode.PrintPath(path);
break;
}
if (top.Nodes.Any() && !CheckIfAllVisited(top.Nodes, visited))
{
foreach (FrogNode node in top.Nodes)
{
if (!visited.Contains(node))
{
path.Push(node);
break;
}
}
}
else
{
visited.Add(path.Pop());
}
}
}
public FrogNode(FrogNode node)
{
Frogs = new List <char>(node.Frogs);
Nodes = new List <FrogNode>();
ZeroPos = node.ZeroPos;
}
