graph_t* graph_new(int num_nodes);
halfedge_t*graph_add_edge(node_t*from, node_t*to, weight_t forward_weight, weight_t backward_weight);
weight_t graph_maxflow(graph_t*graph, node_t*pos1, node_t*pos2);
graph_t* graph_new(int num_nodes);
halfedge_t*graph_add_edge(node_t*from, node_t*to, weight_t forward_weight, weight_t backward_weight);
weight_t graph_maxflow(graph_t*graph, node_t*pos1, node_t*pos2);