Create spanning tree

solved OpenGenus#6586

spanning tree

@@ -0,0 +1,106 @@
+#include<iostream>
+#include<math.h>
+using namespace std;
+
+class span {
+    int* parent;
+    int* rank;
+
+public:
+    span(int n)
+    {
+        parent = new int[n];
+        rank = new int[n];
+
+        for (int i = 0; i < n; i++) {
+            parent[i] = -1;
+            rank[i] = 1;
+        }
+    }
+
+
+    int find(int i)
+    {
+        if (parent[i] == -1)
+            return i;
+
+        return parent[i] = find(parent[i]);
+    }
+
+
+    void unite(int x, int y)
+    {
+        int s1 = find(x);
+        int s2 = find(y);
+
+        if (s1 != s2) {
+            if (rank[s1] < rank[s2]) {
+                parent[s1] = s2;
+            }
+            else if (rank[s1] > rank[s2]) {
+                parent[s2] = s1;
+            }
+            else {
+                parent[s2] = s1;
+                rank[s1] += 1;
+            }
+        }
+    }
+};
+
+class Graph {
+    vector<vector<int> > edgelist;
+    int V;
+
+public:
+    Graph(int V) { this->V = V; }
+
+
+    void addEdge(int x, int y, int w)
+    {
+        edgelist.push_back({ w, x, y });
+    }
+
+    void kruskals_mst()
+    {
+
+        sort(edgelist.begin(), edgelist.end());
+
+
+        span s(V);
+        int ans = 0;
+        cout << "Following are the edges in the "
+                "constructed MST"
+             << endl;
+        for (auto edge : edgelist) {
+            int w = edge[0];
+            int x = edge[1];
+            int y = edge[2];
+
+
+            if (s.find(x) != s.find(y)) {
+                s.unite(x, y);
+                ans += w;
+                cout << x << " -- " << y << " == " << w
+                     << endl;
+            }
+        }
+        cout << "Minimum Cost Spanning Tree: " << ans;
+    }
+};
+
+
+int main()
+{
+    Graph g(4);
+    g.addEdge(0, 1, 10);
+    g.addEdge(1, 3, 15);
+    g.addEdge(2, 3, 4);
+    g.addEdge(2, 0, 6);
+    g.addEdge(0, 3, 5);
+
+
+    g.kruskals_mst();
+
+    return 0;
+}