public static void Part2()
{
//The bridge you've built isn't long enough; you can't jump the rest of the way.
//In the example above, there are two longest bridges:
// 0 / 2--2 / 2--2 / 3--3 / 4
// 0 / 2--2 / 2--2 / 3--3 / 5
//Of them, the one which uses the 3 / 5 component is stronger; its strength is 0 + 2 + 2 + 2 + 2 + 3
// + 3 + 5 = 19.
//What is the strength of the longest bridge you can make? If you can make multiple bridges of the
//longest length, pick the strongest one.
IList <Node2> components = new List <Node2>();
int maxStrengthLongest = 0;
int longestBridge = 0;
string line;
using (StringReader reader = new StringReader(Input))
{
while ((line = reader.ReadLine()) != null)
{
var component = line.Split('/').Select(p => int.Parse(p));
components.Add(new Node2 {
A = component.First(), B = component.Last()
});
}
}
var roots = components.Where(c => c.A == 0 || c.B == 0);
foreach (Node2 rootNode in roots)
{
Node2 root = new Node2
{
A = rootNode.A == 0 ? rootNode.A : rootNode.B,
B = rootNode.A == 0 ? rootNode.B : rootNode.A,
};
root.AddChildren(ref components, ref maxStrengthLongest, ref longestBridge);
}
Debug.WriteLine("Max length: " + longestBridge);
Debug.WriteLine("Max strength: " + maxStrengthLongest);
}
public void AddChildren(ref IList <Node2> components, ref int maxStrength, ref int maxLength)
{
foreach (Node2 component in components.Where(c => !InChain(c)))
{
if (component.A == B)
{
var node = new Node2 {
A = component.A, B = component.B, Parent = this
};
Children.Add(node);
if (node.Length > maxLength)
{
maxLength = node.Length;
maxStrength = node.Strength;
}
if (node.Length == maxStrength && node.Strength > maxStrength)
{
maxStrength = node.Length;
}
node.AddChildren(ref components, ref maxStrength, ref maxLength);
}
if (component.B == B)
{
var node = new Node2 {
A = component.B, B = component.A, Parent = this
};
Children.Add(node);
if (node.Length > maxLength)
{
maxLength = node.Length;
maxStrength = node.Strength;
}
if (node.Length == maxStrength && node.Strength > maxStrength)
{
maxStrength = node.Length;
}
node.AddChildren(ref components, ref maxStrength, ref maxLength);
}
}
}