Added graph data structure and DFS algorithm

main.go

@@ -4,6 +4,7 @@ package main
 // import formatted I/O package
 import (
 	"algos/src/Algo/other/permutaions"
+	"algos/src/Algo/search/graph"
 	"fmt"
 )
 
@@ -21,7 +22,7 @@ func compareA(a float64, b float64) bool {
 
 
 // Any program in go start with main function inside "main' package
-// You can put main inside any other folders like src/main/main.go
+// You can put main inside any other folders like src/main/graph_test.go
 func main()  {
 	fmt.Printf("Hello World!\n")
 
@@ -58,4 +59,20 @@ func main()  {
 	stringVar := "abcd"
 	permutationStrings := permutaions.HeapsPermutation(4, stringVar)
 	fmt.Println(permutationStrings)
+
+
+	G := graph.NewGraph()
+
+	v0 := G.AddVertex("A")
+	v1 := G.AddVertex("B")
+	v2 := G.AddVertex("C")
+	v3 := G.AddVertex("D")
+	G.AddEdge(v0, v1)
+	G.AddEdge(v0, v2)
+	G.AddEdge(v1, v2)
+	G.AddEdge(v2, v0)
+	G.AddEdge(v2, v3)
+	G.AddEdge(v3, v3)
+	G.PrintGraph()
+	G.Dfs(v2)
 }

src/Algo/search/graph/graph.go

@@ -1 +1,74 @@
 package graph
+
+import (
+	"fmt"
+)
+
+// Vertex Structure
+type Vertex struct {
+	Label   string
+	AdjList []*Vertex
+}
+
+// Graph Entity
+type Graph struct {
+	VertexCount int
+	Vertices    []*Vertex
+}
+
+// NewGraph returns
+func NewGraph() *Graph {
+	return new(Graph)
+}
+
+// AddVertex  adds new vertex to G of given label and returns that vertex
+func (g *Graph) AddVertex(label string) *Vertex {
+	vertex := new(Vertex)
+	vertex.Label = label
+	g.VertexCount = g.VertexCount + 1
+	g.Vertices = append(g.Vertices, vertex)
+	return vertex
+}
+
+// AddEdge creates an edge between two vertex
+func (g *Graph) AddEdge(srcVertex, dstVertex *Vertex) *Vertex {
+	srcVertex.AdjList = append(srcVertex.AdjList, dstVertex)
+	return srcVertex
+}
+
+// Dfs performs Depth Fist Search
+func (g *Graph) Dfs(vertex *Vertex) {
+	//visited := []bool{false, false}
+
+	visited := make(map[string]bool)
+	for i := range g.Vertices {
+		visited[g.Vertices[i].Label] = false
+	}
+	g.dfsUtil(vertex, visited)
+
+}
+
+// dfsUtil is utility for Dfs
+func (g *Graph) dfsUtil(vertex *Vertex, visited map[string]bool) {
+
+	visited[vertex.Label] = true
+	fmt.Printf("\n%s ", vertex.Label)
+	for _, v := range vertex.AdjList {
+		if visited[v.Label] == false {
+			g.dfsUtil(v, visited)
+		}
+	}
+
+}
+
+// PrintGraph prints the create graph G
+func (g *Graph) PrintGraph() {
+	fmt.Printf("Number of vertices %d\n", g.VertexCount)
+	for _, v := range g.Vertices {
+		fmt.Printf("Vertex: %s\n Adjency list \n", v.Label)
+		for _, adv := range v.AdjList {
+			fmt.Printf("%s, ", adv.Label)
+		}
+		fmt.Printf("\n")
+	}
+}

src/Algo/search/graph/graph_test.go

@@ -1 +1,24 @@
 package graph
+
+import (
+	"testing"
+)
+
+func TestNewGraph(t *testing.T) {
+
+	G := NewGraph()
+
+	v0 := G.AddVertex("A")
+	v1 := G.AddVertex("B")
+	v2 := G.AddVertex("C")
+	v3 := G.AddVertex("D")
+	G.AddEdge(v0, v1)
+	G.AddEdge(v0, v2)
+	G.AddEdge(v1, v2)
+	G.AddEdge(v2, v0)
+	G.AddEdge(v2, v3)
+	G.AddEdge(v3, v3)
+	G.PrintGraph()
+	G.Dfs(v2)
+
+}