Added Graph.java

Author: SlyyJavii

Graph.java

@@ -0,0 +1,58 @@
+
+public class Graph {
+    private int[][] edges; // matrix
+    private int nV; // number of vertices
+    private int nE; // number of edges
+
+    // constructor with n vertices
+    public Graph(int nV) {
+        this.nV = nV;
+        this.nE = 0;
+        edges = new int[nV][nV]; // initialize matrix with 0
+    }
+
+    // method to check if a vertex is valid
+    private boolean validV(int v) {
+        return (v >= 0 && v < nV);
+    }
+
+    // method to insert edge
+    public void insertEdge(int v, int w) {
+        if (validV(v) && validV(w) && edges[v][w] == 0) {
+            edges[v][w] = 1;
+            edges[w][v] = 1; // undirected graph
+            nE++;
+        }
+    }
+
+    // method to remove edge
+    public void removeEdge(int v, int w) {
+        if (validV(v) && validV(w) && edges[v][w] == 1) {
+            edges[v][w] = 0;
+            edges[w][v] = 0;
+            nE--;
+        }
+    }
+
+    // method to check if two vertices are adjacent
+    public boolean adjacent(int v, int w) {
+        return validV(v) && validV(w) && edges[v][w] != 0;
+    }
+
+    // method to display graph
+    public void showGraph() {
+        System.out.println("Number of vertices: " + nV);
+        System.out.println("Number of edges: " + nE);
+        for (int i = 0; i < nV; i++) {
+            for (int j = i + 1; j < nV; j++) {
+                if (edges[i][j] == 1) {
+                    System.out.println("Edges " + i + " - " + j);
+                }
+            }
+        }
+    }
+
+    public int getNumVertices() {
+        return nV;
+    }
+}