唯一做出来的第二道题 ``` int findMinCnt(unordered_map<int, vector<pair<int, bool>>>& tree, int root) { //get from root min nums of workers need send to sub tree //返回以当前为根发送最少数量 if (tree.find(root) == tree.end()) { return 0; } auto sub_roots = tree[root]; int ret = 0; for (auto [sub_root, path_ok] : sub_roots) { if (path_ok) { ret += max(findMinCnt(tree, sub_root), 0); } else { ret += max(findMinCnt(tree, sub_root), 1); } } return ret; } ```