Naive approach for Mother Vertex

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1

V is the number of vertices

vector adj[ ] stores the information of vertex connectivity. Suppose, we have an example as : 1 0, 0 2, 2 1, 0 3, 3 4 where each pair indicate the connection. For this, we can see that the vertex 0 is a mother vertex, but the code is returning that there is no mother vertex. I cannot figure out the reason.

//Driver Function


void dfsUtil(int i,int vis[],vector<int> adj[])
{
    vis[i]=1;
    for(int j=0;j<adj[i].size();j++)
        if(!vis[j])
            dfsUtil(j,vis,adj);
}

int dfs(int i,int V,vector<int> adj[])
{
    int vis[V];
    for(int j=0;j<V;j++)
        vis[j]=0;
    dfsUtil(i,vis,adj);
    for(int j=0;j<V;j++)
        if(!vis[j])
            return 0;
    return 1;
}

int findMother(int V, vector<int> adj[]) 
{ 
    for(int i=0;i<V;i++)
        if(dfs(i,V,adj))
            return i;
    return -1;
}