Fix a bug in the index min pq

cschen1205 · cschen1205 · commit ea95cde9a9f9 · 2017-05-17T09:35:25.000+08:00
diff --git a/Algorithms/DataStructures/Queue/IndexMinPQ.cs b/Algorithms/DataStructures/Queue/IndexMinPQ.cs
@@ -92,7 +92,7 @@ public void DecreaseKey(int index, T item)
 
         public bool Contains(int index)
         {
-            return qp[index] == -1;
+            return qp[index] != -1;
         }
 
         private void Sink(int k)
diff --git a/Algorithms/Graphs/MST/EagerPrim.cs b/Algorithms/Graphs/MST/EagerPrim.cs
@@ -40,7 +40,7 @@ private void Visit(WeightedGraph G, int v)
                 int w = e.other(v);
                 if (!marked[w])
                 {
-                    if (pq.Contains(w))
+                    if (!pq.Contains(w))
                     {
                         pq.Insert(w, e);
                     }
diff --git a/AlgorithmsUnitTest/Graphs/ShortestPaths/DijkstraUnitTest.cs b/AlgorithmsUnitTest/Graphs/ShortestPaths/DijkstraUnitTest.cs
@@ -24,10 +24,15 @@ public void Test()
             Dijkstra dijkstra = new Dijkstra(G, 0);
             for(var v=1; v < G.V(); ++v)
             {
-                if (!dijkstra.HasPathTo(v)) continue;
+                if (!dijkstra.HasPathTo(v))
+                {
+                    Console.WriteLine("Path not found for {0}", v);
+                    continue;
+                }
                 IEnumerable<Edge> path = dijkstra.PathTo(v);
 
                 console.WriteLine(ToString(path));
+                Console.WriteLine(ToString(path));
             }
         }
 

Original file line number	Diff line number	Diff line change
`@@ -92,7 +92,7 @@ public void DecreaseKey(int index, T item)`
`92`	`92`
`93`	`93`	`public bool Contains(int index)`
`94`	`94`	`{`
`95`		`- return qp[index] == -1;`
	`95`	`+ return qp[index] != -1;`
`96`	`96`	`}`
`97`	`97`
`98`	`98`	`private void Sink(int k)`
Original file line number	Diff line number	Diff line change
`@@ -40,7 +40,7 @@ private void Visit(WeightedGraph G, int v)`
`40`	`40`	`int w = e.other(v);`
`41`	`41`	`if (!marked[w])`
`42`	`42`	`{`
`43`		`- if (pq.Contains(w))`
	`43`	`+ if (!pq.Contains(w))`
`44`	`44`	`{`
`45`	`45`	`pq.Insert(w, e);`
`46`	`46`	`}`
Original file line number	Diff line number	Diff line change
`@@ -24,10 +24,15 @@ public void Test()`
`24`	`24`	`Dijkstra dijkstra = new Dijkstra(G, 0);`
`25`	`25`	`for(var v=1; v < G.V(); ++v)`
`26`	`26`	`{`
`27`		`- if (!dijkstra.HasPathTo(v)) continue;`
	`27`	`+ if (!dijkstra.HasPathTo(v))`
	`28`	`+ {`
	`29`	`+ Console.WriteLine("Path not found for {0}", v);`
	`30`	`+ continue;`
	`31`	`+ }`
`28`	`32`	`IEnumerable<Edge> path = dijkstra.PathTo(v);`
`29`	`33`
`30`	`34`	`console.WriteLine(ToString(path));`
	`35`	`+ Console.WriteLine(ToString(path));`
`31`	`36`	`}`
`32`	`37`	`}`
`33`	`38`