Update HopcroftKarp.cs

justcoding121 · justcoding121 · commit a9936c791be2 · 2021-04-21T02:44:42.000-06:00
diff --git a/src/Advanced.Algorithms/Graph/Matching/HopcroftKarp.cs b/src/Advanced.Algorithms/Graph/Matching/HopcroftKarp.cs
@@ -81,14 +81,14 @@ private List<T> bfs(IGraph<T> graph,
             foreach (var vertex in partitions[1])
             {
                 //if this left vertex is free
-                if (!leftToRightMatchEdges.ContainsKey(vertex))
+                if (!leftToRightMatchEdges.ContainsKey(vertex) && !visited.Contains(vertex))
                 {
                     queue.Enqueue(vertex);
-                    visited.Add(vertex);
-
+                    
                     while (queue.Count > 0)
                     {
                         var current = queue.Dequeue();
+                        visited.Add(vertex);
 
                         //unmatched edges left to right
                         foreach (var leftToRightEdge in graph.GetVertex(current).Edges)

Original file line number	Diff line number	Diff line change
`@@ -81,14 +81,14 @@ private List<T> bfs(IGraph<T> graph,`
`81`	`81`	`foreach (var vertex in partitions[1])`
`82`	`82`	`{`
`83`	`83`	`//if this left vertex is free`
`84`		`- if (!leftToRightMatchEdges.ContainsKey(vertex))`
	`84`	`+ if (!leftToRightMatchEdges.ContainsKey(vertex) && !visited.Contains(vertex))`
`85`	`85`	`{`
`86`	`86`	`queue.Enqueue(vertex);`
`87`		`- visited.Add(vertex);`
`88`		`-`
	`87`	`+`
`89`	`88`	`while (queue.Count > 0)`
`90`	`89`	`{`
`91`	`90`	`var current = queue.Dequeue();`
	`91`	`+ visited.Add(vertex);`
`92`	`92`
`93`	`93`	`//unmatched edges left to right`
`94`	`94`	`foreach (var leftToRightEdge in graph.GetVertex(current).Edges)`