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Optimize multiroute

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This commit is contained in:
Jack Kanarish
2017-12-20 20:28:58 -05:00
parent 222365f210
commit 02cae250a6
1 changed files with 176 additions and 100 deletions
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276
ICD.Common.Utils/RecursionUtils.cs
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@@ -3,127 +3,203 @@ using System.Collections.Generic;
using System.Linq;
using ICD.Common.Properties;
using ICD.Common.Utils.Collections;
using ICD.Common.Utils.Extensions;
namespace ICD.Common.Utils
{
public static class RecursionUtils
{
/// <summary>
/// Returns all of the nodes in the tree via breadth-first search.
/// </summary>
/// <typeparam name="T"></typeparam>
/// <param name="root"></param>
/// <param name="getChildren"></param>
/// <returns></returns>
public static IEnumerable<T> BreadthFirstSearch<T>(T root, Func<T, IEnumerable<T>> getChildren)
{
if (getChildren == null)
throw new ArgumentNullException("getChildren");
public static class RecursionUtils
{
/// <summary>
/// Returns all of the nodes in the tree via breadth-first search.
/// </summary>
/// <typeparam name="T"></typeparam>
/// <param name="root"></param>
/// <param name="getChildren"></param>
/// <returns></returns>
public static IEnumerable<T> BreadthFirstSearch<T>(T root, Func<T, IEnumerable<T>> getChildren)
{
if (getChildren == null)
throw new ArgumentNullException("getChildren");
Queue<T> process = new Queue<T>();
process.Enqueue(root);
Queue<T> process = new Queue<T>();
process.Enqueue(root);
while (process.Count > 0)
{
T current = process.Dequeue();
yield return current;
while (process.Count > 0)
{
T current = process.Dequeue();
yield return current;
foreach (T child in getChildren(current))
process.Enqueue(child);
}
}
foreach (T child in getChildren(current))
process.Enqueue(child);
}
}
/// <summary>
/// Returns the shortest path from root to destination via breadth-first search.
/// </summary>
/// <typeparam name="T"></typeparam>
/// <param name="root"></param>
/// <param name="destination"></param>
/// <param name="getChildren"></param>
/// <returns></returns>
[CanBeNull]
public static IEnumerable<T> BreadthFirstSearchPath<T>(T root, T destination, Func<T, IEnumerable<T>> getChildren)
{
if (getChildren == null)
throw new ArgumentNullException("getChildren");
/// <summary>
/// Returns the shortest path from root to destination via breadth-first search.
/// </summary>
/// <typeparam name="T"></typeparam>
/// <param name="root"></param>
/// <param name="destination"></param>
/// <param name="getChildren"></param>
/// <returns></returns>
[CanBeNull]
public static IEnumerable<T> BreadthFirstSearchPath<T>(T root, T destination, Func<T, IEnumerable<T>> getChildren)
{
if (getChildren == null)
throw new ArgumentNullException("getChildren");
return BreadthFirstSearchPath(root, destination, getChildren, EqualityComparer<T>.Default);
}
return BreadthFirstSearchPath(root, destination, getChildren, EqualityComparer<T>.Default);
}
/// <summary>
/// Returns the shortest path from root to destination via breadth-first search.
/// </summary>
/// <typeparam name="T"></typeparam>
/// <param name="root"></param>
/// <param name="destination"></param>
/// <param name="getChildren"></param>
/// <param name="comparer"></param>
/// <returns></returns>
[CanBeNull]
public static IEnumerable<T> BreadthFirstSearchPath<T>(T root, T destination, Func<T, IEnumerable<T>> getChildren,
IEqualityComparer<T> comparer)
{
if (getChildren == null)
throw new ArgumentNullException("getChildren");
[NotNull]
public static Dictionary<T2, IEnumerable<T>> BreadthFirstSearchManyDestinations<T, T2>(T root, Dictionary<T2, T> destinations, Func<T, IEnumerable<T>> getChildren)
{
if (getChildren == null)
throw new ArgumentNullException("getChildren");
if (comparer == null)
throw new ArgumentNullException("comparer");
return BreadthFirstSearchPathManyDestinations(root, destinations, getChildren, EqualityComparer<T>.Default);
}
// Edge case - root and destination are the same
if (comparer.Equals(root, destination))
return new[] {root};
/// <summary>
/// Returns the shortest path from root to destination via breadth-first search.
/// </summary>
/// <typeparam name="T"></typeparam>
/// <param name="root"></param>
/// <param name="destination"></param>
/// <param name="getChildren"></param>
/// <param name="comparer"></param>
/// <returns></returns>
[CanBeNull]
public static IEnumerable<T> BreadthFirstSearchPath<T>(T root, T destination, Func<T, IEnumerable<T>> getChildren,
IEqualityComparer<T> comparer)
{
if (getChildren == null)
throw new ArgumentNullException("getChildren");
Queue<T> queue = new Queue<T>();
queue.Enqueue(root);
if (comparer == null)
throw new ArgumentNullException("comparer");
Dictionary<T, T> nodeParents = new Dictionary<T, T>();
// Edge case - root and destination are the same
if (comparer.Equals(root, destination))
return new[] { root };
while (queue.Count > 0)
{
T current = queue.Dequeue();
Queue<T> queue = new Queue<T>();
queue.Enqueue(root);
foreach (T node in getChildren(current))
{
if (nodeParents.ContainsKey(node))
continue;
Dictionary<T, T> nodeParents = new Dictionary<T, T>();
queue.Enqueue(node);
nodeParents.Add(node, current);
while (queue.Count > 0)
{
T current = queue.Dequeue();
// Found a path to the destination
if (comparer.Equals(node, destination))
return GetPath(destination, nodeParents).Reverse();
}
}
foreach (T node in getChildren(current))
{
if (nodeParents.ContainsKey(node))
continue;
return null;
}
queue.Enqueue(node);
nodeParents.Add(node, current);
/// <summary>
/// Walks through a map of nodes from the starting point.
/// </summary>
/// <typeparam name="T"></typeparam>
/// <param name="start"></param>
/// <param name="nodeParents"></param>
/// <returns></returns>
private static IEnumerable<T> GetPath<T>(T start, IDictionary<T, T> nodeParents)
{
IcdHashSet<T> visited = new IcdHashSet<T>();
// Found a path to the destination
if (comparer.Equals(node, destination))
return GetPath(destination, nodeParents).Reverse();
}
}
while (true)
{
yield return start;
visited.Add(start);
return null;
}
T next;
if (!nodeParents.TryGetValue(start, out next))
break;
[NotNull]
public static Dictionary<T2, IEnumerable<T>> BreadthFirstSearchPathManyDestinations<T, T2>(T root, Dictionary<T2, T> destinations,
Func<T, IEnumerable<T>> getChildren,
IEqualityComparer<T> comparer)
{
if (getChildren == null)
throw new ArgumentNullException("getChildren");
if (visited.Contains(next))
break;
if (comparer == null)
throw new ArgumentNullException("comparer");
start = next;
}
}
}
Dictionary<T2, T> destinationsToBeProcessed = new Dictionary<T2, T>(destinations);
List<T> destinationsProcessed = new List<T>();
Dictionary<T2, IEnumerable<T>> pathsToReturn = new Dictionary<T2, IEnumerable<T>>();
//Edge case, root is the destination
foreach (var destination in destinationsToBeProcessed.Where(destination => comparer.Equals(root, destination.Value)))
{
destinationsProcessed.Add(destination.Value);
pathsToReturn.Add(destination.Key, new[] { root });
}
foreach (var destination in destinationsProcessed)
{
destinationsToBeProcessed.RemoveValue(destination);
}
destinationsProcessed.Clear();
if (destinationsToBeProcessed.Count == 0)
{
return pathsToReturn;
}
Queue<T> queue = new Queue<T>();
queue.Enqueue(root);
Dictionary<T, T> nodeParents = new Dictionary<T, T>();
while (queue.Count > 0)
{
T current = queue.Dequeue();
foreach (T node in getChildren(current).Where(node => !nodeParents.ContainsKey(node)))
{
queue.Enqueue(node);
nodeParents.Add(node, current);
foreach (var destination in destinationsToBeProcessed.Where(destination => comparer.Equals(node, destination.Value)))
{
destinationsProcessed.Add(destination.Value);
pathsToReturn.Add(destination.Key, GetPath(destination.Value, nodeParents).Reverse());
}
foreach (var destination in destinationsProcessed)
{
destinationsToBeProcessed.RemoveValue(destination);
}
destinationsProcessed.Clear();
if (destinationsToBeProcessed.Count == 0)
{
return pathsToReturn;
}
}
}
return pathsToReturn;
}
/// <summary>
/// Walks through a map of nodes from the starting point.
/// </summary>
/// <typeparam name="T"></typeparam>
/// <param name="start"></param>
/// <param name="nodeParents"></param>
/// <returns></returns>
private static IEnumerable<T> GetPath<T>(T start, IDictionary<T, T> nodeParents)
{
IcdHashSet<T> visited = new IcdHashSet<T>();
while (true)
{
yield return start;
visited.Add(start);
T next;
if (!nodeParents.TryGetValue(start, out next))
break;
if (visited.Contains(next))
break;
start = next;
}
}
}
}