Method reset

code/graph/edmonds_karps_mcmf.cpp:11–11

  int n; vi head; vector<edge> e, e_store;
  flow_network(int _n) : n(_n), head(n,-1) { }
  void reset() { e = e_store; }
  void add_edge(int u, int v, int cost, int uv, int vu=0) {
    e.push_back(edge(v, uv, cost, head[u]));
    head[u] = (int)size(e)-1;