蓝桥杯c++-蓝桥杯竞赛练习之算法提高题卡勒沃夫之弱水路三千.zip

#include <iostream> #include <algorithm> #include <set> #include <map> using namespace std; int main() { int k, n; cin >> k; while (k--) { string ans = ""; cin >> n; map<string, set<string> > m; map<string, int> vis; for (int i = 0; i < n; i++) { string s1, s2; cin >> s1 >> s2; m[s1]; m[s2].insert(s1); } while (1) { int check = 0; for (map<string, set<string> >::iterator i = m.begin(); i != m.end(); i++) { string girl = i->first; if (vis[girl] == 0 && m[girl].size() == 0) { check = 1; vis[girl] = 1; for (map<string, set<string> >::iterator j = m.begin(); j != m.end(); j++) { j->second.erase(girl); } ans = ans + girl + " "; break; } } if (check == 0) break; } cout << ans.substr(0, ans.length() - 1) << endl; } return 0; }