int *visited;
int **adj;
int V;
stack S; //stack of nodes (indices)

// iterative
void DFSearch()
{
    int i, k;
    for (k = 0; k < V; k++) visited[k] = 0;
    
    for (k = V-1; k >= 0; k--) {
        push(S, k);
    }
    
    while (size(S) > 0) {
        k = pop(S);
        if (!visited[k]) {
            visited[k] = 1;
            /*
               Do something to VISIT node k
             */
            for (i = V-1; i >= 0; i--)
                if (adj[k][i]) push(S, i);
        }
    }
}