graph

Author: xiaomeng79

data-structures/graph/directed_graph.go

@@ -15,15 +15,14 @@ func NewDirected() *DirGraph {
 	}
 }
 
+//入度
 func (g *graph) GetPredecessors(vertex VertexId) VerticesIterable {
 	iterator := func() <-chan VertexId {
 		ch := make(chan VertexId)
 		go func() {
-			if connected, ok := g.edges[vertex]; ok {
-				for VertexId, _ := range connected {
-					if g.CheckEdge(VertexId, vertex) {
-						ch <- VertexId
-					}
+			for VertexId, _ := range g.edges {
+				if g.CheckEdge(VertexId, vertex) {
+					ch <- VertexId
 				}
 			}
 			close(ch)
@@ -34,6 +33,7 @@ func (g *graph) GetPredecessors(vertex VertexId) VerticesIterable {
 	return VerticesIterable(&VerticesIterableHelp{iter: iterator})
 }
 
+//出度
 func (g *graph) GetSuccessors(vertex VertexId) VerticesIterable {
 	iterator := func() <-chan VertexId {
 		ch := make(chan VertexId)

data-structures/graph/graph.go

@@ -81,6 +81,10 @@ func (g *graph) RemoveVertex(vertex VertexId) error {
 	if !g.CheckVertex(vertex) {
 		return errors.New("unknow vertex")
 	}
+	//先删除边
+	for _to, _ := range g.edges[vertex] {
+		g.RemoveEdge(vertex, _to)
+	}
 	delete(g.edges, vertex)
 	for _, connectedVertices := range g.edges {
 		delete(connectedVertices, vertex)
@@ -111,6 +115,10 @@ func (g *graph) AddEdge(from, to VertexId, weight int) error {
 	if !g.CheckVertex(from) || !g.CheckVertex(to) {
 		return errors.New("vertices not exist")
 	}
+	//判断边存在不
+	if g.edges[from][to] > 0 {
+		return errors.New("edge  exist")
+	}
 	g.edges[from][to] = weight
 	if !g.isDirected {
 		g.edges[to][from] = weight

data-structures/graph/graph_test.go

@@ -1 +1,92 @@
 package graph
+
+import (
+	"github.com/stretchr/testify/assert"
+	"testing"
+)
+
+func TestNewUndirected(t *testing.T) {
+	g := NewUndirected()
+	//增加顶点
+	for i := 0; i < 10; i++ {
+		g.AddVertex(VertexId(i))
+	}
+	assert.Equal(t, 10, g.VerticesCount())
+	//增加边
+	for i := 0; i < 10; i++ {
+		g.AddEdge(VertexId(i), VertexId(i%2), 1)
+	}
+	//
+	assert.Equal(t, true, g.CheckEdge(2, 0))
+	assert.Equal(t, false, g.CheckEdge(2, 1))
+	assert.Equal(t, 1, g.GetEdgeWeight(2, 0))
+	//删除顶点
+	assert.NoError(t, g.RemoveVertex(VertexId(2)))
+	assert.Equal(t, false, g.CheckVertex(VertexId(2)))
+	assert.Equal(t, false, g.CheckEdge(2, 0))
+	//增加边，存在修改
+	assert.NoError(t, g.AddEdge(3, 0, 1))
+	assert.Equal(t, true, g.CheckEdge(3, 0))
+	//删除边
+	assert.NoError(t, g.RemoveEdge(3, 0))
+	assert.Equal(t, false, g.CheckEdge(3, 0))
+
+	//统计边
+	c := g.EdgesIter()
+	countEdge := 0
+	for _ = range c {
+		countEdge++
+	}
+	assert.Equal(t, countEdge, g.EdgesCount())
+
+}
+
+func TestNewDirected(t *testing.T) {
+	g := NewDirected()
+	//增加顶点
+	for i := 0; i < 10; i++ {
+		g.AddVertex(VertexId(i))
+	}
+	assert.Equal(t, 10, g.VerticesCount())
+	//增加边
+	for i := 0; i < 10; i++ {
+		g.AddEdge(VertexId(i), VertexId(i%2), 1)
+	}
+	//
+	assert.Equal(t, true, g.CheckEdge(2, 0))
+	assert.Equal(t, false, g.CheckEdge(2, 1))
+	assert.Equal(t, 1, g.GetEdgeWeight(2, 0))
+	//删除顶点
+	assert.NoError(t, g.RemoveVertex(VertexId(2)))
+	assert.Equal(t, false, g.CheckVertex(VertexId(2)))
+	assert.Equal(t, false, g.CheckEdge(2, 0))
+	//增加边，存在修改
+	assert.NoError(t, g.AddEdge(3, 0, 1))
+	assert.Equal(t, true, g.CheckEdge(3, 0))
+	//删除边
+	assert.NoError(t, g.RemoveEdge(3, 0))
+	assert.Equal(t, false, g.CheckEdge(3, 0))
+
+	//统计边
+	c := g.EdgesIter()
+	countEdge := 0
+	for _ = range c {
+		countEdge++
+	}
+	assert.Equal(t, countEdge, g.EdgesCount())
+	//查看
+	//for p := range g.EdgesIter() {
+	//	t.Log(p)
+	//}
+	//入度
+	gp := g.GetPredecessors(VertexId(1)).VerticesIter()
+	for p := range gp {
+		if p != 3 && p != 5 && p != 7 && p != 9 {
+			t.Error()
+		}
+	}
+
+	for p := range g.GetSuccessors(VertexId(4)).VerticesIter() {
+		assert.Equal(t, VertexId(0), p)
+	}
+}