| 14 | } |
| 15 | |
| 16 | void update_cost(int u, int v, int c) { |
| 17 | if (parent[v].first == u) |
| 18 | swap(u, v); |
| 19 | |
| 20 | assert(parent[u].first == v); |
| 21 | parent[u] = ii(v, c); |
| 22 | |
| 23 | for (int i = 0; i < size(adj[u]); i++) |
| 24 | if (adj[u][i].first == v) |
| 25 | adj[u][i] = ii(v, c); |
| 26 | |
| 27 | for (int i = 0; i < size(adj[v]); i++) |
| 28 | if (adj[v][i].first == u) |
| 29 | adj[v][i] = ii(u, c); |
| 30 | } |
| 31 | |
| 32 | int lca(int u, int v) { |
| 33 | vi uat, vat; int res = -1; |