Loop in Graph(Union-Find algorithm)

This code create a graph and then ideitifies is there is any loop in the graph.

#include<iostream.h>

class Edge{
public:
int s;
int d;
};

class Graph{
public:
int v;
int e;
Edge* edge;
};



Graph* createGraph(int v,int e)
{
Graph *g= new Graph;
g->v = v;
g->e=e;
g->edge = new Edge[e];
return g;
}

int findParent(int *p,int i)
{
if(p[i]==-1)
return i;
return findParent(p,p[i]);
}

void unionSet(int *p,int s,int d)
{
int x = findParent(p,s);
int y = findParent(p,d);

p[x]=y;
}

int isCycle(Graph *g)
{
int *p=new int[g->v];
memset(p,-1,sizeof(int)*g->v);

for(int i=0;i<g->e;i++)
{
int x = findParent(p,g->edge[i].s);
int y = findParent(p,g->edge[i].d);

if(x==y)
return 1;
unionSet(p,x,y);
}
return 0;
}

// Driver program to test above functions
int main()
{
    /* Let us create following graph
         0
        |  
        |    
        1-----2 */

//three vertices (0,1,2) and two edges (0-1,1-2)    
Graph* graph = createGraph(3, 2);

    // add edge 0-1
    graph->edge[0].s = 0;
    graph->edge[0].d = 1;

    // add edge 1-2
    graph->edge[1].s = 1;
    graph->edge[1].d = 2;

    // add edge 0-2
    //graph->edge[2].s = 0;
    //graph->edge[2].d = 2;

    if (isCycle(graph))
        printf( "Graph contains cycle" );
    else
        printf( "Graph doesn't contain cycle" );

    return 0;
}