void tarjanVisit_aux(Graph g, int from, int to) {
if (low[to] == INT_MAX || stack_contains(to)) {
if(low[to] == INT_MAX) {
tarjanVisit(g, to);
}
low[from]=min(low[from],low[to]);
}
}
// Tarjan's Algorithm from wikipedia
static uint32_t strongly_connected(struct stack* stack, remodel_node_t* node, uint32_t* index) {
node->index = *index;
node->low_index = *index;
(*index)++;
stack_push(stack, node);
ht_entry_t* entry;
ht_iterator_t iter = HT_ITERATOR_INITIALIZER;
while (ht_next(node->children, &iter, &entry)) {
remodel_edge_t* edge = entry->value;
assert(edge->from == node);
if (edge->to->index == 0) {
strongly_connected(stack, edge->to, index);
node->low_index = min(node->low_index, edge->to->low_index);
} else if(stack_contains(stack, edge->to)) {
node->low_index = min(node->low_index, edge->to->index);
}
}
if (node->low_index == node->index) {
array_t* component = array_new();
remodel_node_t* w;
do {
assert(!stack_is_empty(stack));
w = stack_pop(stack);
array_append(component, w);
} while (w != node);
if (component->len > 1) {
fprintf(stderr, "error: dependency graph contains cycle:\n");
fprintf(stderr, " [");
for (uint32_t i = 0; i < component->len; i++) {
remodel_node_t* n = array_get(component, i);
fprintf(stderr, "%s", n->name);
if (i != component->len - 1) {
fprintf(stderr, ", ");
}
}
fprintf(stderr, "]\n");
array_free(component);
return true;
} else {
array_free(component);
return false;
}
} else {
return false;
}
}
_Bool stack_push_unique(stack * root, void * pointer, char value_type)
{
assert(root != NULL);
return stack_contains(root, pointer, value_type) ? 1 : stack_push(root, pointer, value_type);
}
