package main
import "fmt"
type Edge struct {
startVertex string
endVertex string
value string
}
func insertVertex(vertices *[]string, vertex string) {
*vertices = append(*vertices, vertex)
}
func insertEdge(edgeList *[]Edge, vertex1 string, vertex2 string, edgeVal string) {
var edge Edge
edge.startVertex = vertex1
edge.endVertex = vertex2
edge.value = edgeVal
*edgeList = append(*edgeList, edge)
}
func printEdgeList(edgeList *[]Edge) {
for _, edge := range *edgeList {
fmt.Println("The Edge between "+edge.startVertex+" and "+edge.endVertex+" is "+edge.value );
}
}
func main() {
var vertices[]string
var edgeList[]Edge
// Adding vertices one by one
insertVertex(&vertices, "a")
insertVertex(&vertices, "b")
insertVertex(&vertices, "c")
insertVertex(&vertices, "d")
insertVertex(&vertices, "e")
//Adding edges with values.
insertEdge(&edgeList, "a", "b", "13A")
insertEdge(&edgeList, "b", "a", "45C")
insertEdge(&edgeList, "a", "d", "20F")
insertEdge(&edgeList, "d", "e", "23E")
insertEdge(&edgeList, "e", "b", "12B")
insertEdge(&edgeList, "e", "c", "30F")
insertEdge(&edgeList, "c", "d", "42V")
insertEdge(&edgeList, "a", "c", "18C")
printEdgeList(&edgeList)
}
In the Edge List Data Structure, we are trying to create an Array of Edges.
Where each Edge will contain the start vertex, end vertex and value of the Edge.
Say for Example, the first element of the Edge Array i.e. Bus number 13A, travels from city/Vertex a to city/Vertex b.
So, we will be having two pointers in the first element of Edge Array,
And thus, we have constructed an Edge Structure that contains, start vertex, end vertex and value of the Edge.
type Edge struct {
startVertex string
endVertex string
value string
}We have 2 methods in the Code :
The first method is quite easy to understand.
func insertVertex(vertices *[]string, vertex string) {
*vertices = append(*vertices, vertex)
}Let us take the vertex a to understand the above method.
In the main(...) method, we have created an Array that would contain all the vertices :
var vertices[]string
Then we have taken the vertex a and passed it to the func insertVertex(...) method.
insertVertex(&vertices, "a")
And if we see the func insertVertex(...) method, we would see it accepts two parameters,
'vertices *[]string'
and
'vertex string'.
It is quite self explanatory, vertices *[]string contains the actual Array that contains the vertices and vertex string contains the vertex a.
And we just have one statement in the func insertVertex(...) method.
*vertices = append(*vertices, vertex)
That takes each vertex a and adds to the Array.
After adding all the vertices to the Array, we get the below Array.
Then comes the second method, that adds the edges to the Array(with values). Justifying the name Edge List Data Structure.
func insertEdge(edgeList *[]Edge, vertex1 string, vertex2 string, edgeVal string) {
var edge Edge
edge.startVertex = vertex1
edge.endVertex = vertex2
edge.value = edgeVal
*edgeList = append(*edgeList, edge)
}We will take a small chunk to explain the above method.
Where the bus/edge 13A is traveling from city a to city b.
Now, let us take a look at the main(...) method.
We have created an Array that would store all the edges in that Array.
var edgeList[]Edge
Next, we will pass the edgeList, the start vertex(i.e. a), end vertex(i.e. b) and the value(i.e. 13A) to the void insertEdge(...) method.
insertEdge(&edgeList, "a", "b", "13A");
Now, let us come to the contents of func insertEdge(...) method.
In the first line, we have created the Edge type variable named edge,
var edge Edge
Then, initialised the attributes of the Edge type variable with the actual values,
edge.startVertex = vertex1 edge.endVertex = vertex2 edge.value = edgeVal
And the Edge object looks somewhat like this,
And add the above edge object to the Array,
*edgeList = append(*edgeList, edge)
After adding all the edges to the Array, we get the below Array.
