search: roll distance matrix into paths

search/floydwarshall.go

@@ -46,30 +46,29 @@ func FloydWarshall(g graph.Graph, weight graph.CostFunc) (paths ShortestPaths, o
 	for i := range dist {
 		dist[i] = math.Inf(1)
 	}
-	m := mat64.NewDense(len(nodes), len(nodes), dist)
 	paths = ShortestPaths{
 		nodes:   nodes,
 		indexOf: indexOf,
 
-		dist: m,
+		dist: mat64.NewDense(len(nodes), len(nodes), dist),
 		next: make([][]int, len(nodes)*len(nodes)),
 	}
 	for i, u := range nodes {
-		m.Set(i, i, 0)
+		paths.dist.Set(i, i, 0)
 		for _, v := range from(u) {
 			j := indexOf[v.ID()]
-			m.Set(i, j, weight(edgeTo(u, v)))
+			paths.dist.Set(i, j, weight(edgeTo(u, v)))
 			paths.set(i, j, j)
 		}
 	}
 
 	for k := range nodes {
 		for i := range nodes {
 			for j := range nodes {
-				ij := m.At(i, j)
-				joint := m.At(i, k) + m.At(k, j)
+				ij := paths.dist.At(i, j)
+				joint := paths.dist.At(i, k) + paths.dist.At(k, j)
 				if ij > joint {
-					m.Set(i, j, joint)
+					paths.dist.Set(i, j, joint)
 					paths.set(i, j, paths.at(i, k)...)
 				} else if i != k && k != j && ij-joint == 0 {
 					paths.add(i, j, paths.at(i, k)...)
@@ -80,7 +79,7 @@ func FloydWarshall(g graph.Graph, weight graph.CostFunc) (paths ShortestPaths, o
 
 	ok = true
 	for i := range nodes {
-		if m.At(i, i) < 0 {
+		if paths.dist.At(i, i) < 0 {
 			ok = false
 			break
 		}