摘要：
bool dfs(int u) { vis[u] = 1; for (int i = head[u]; i; i = edge[i].next) { int v = edge[i].to; if (vis[v] == 1) return false; if (vis[v] == 0 && !dfs(v)) return false;... 阅读全文
摘要：
Alice lives in the country where people like to make friends. The friendship is bidirectional and if any two person have no less than k friends in com 阅读全文