Compilare: main.cpp: In constructor 'BipartiteMatching::BipartiteMatching(std::vector<std::vector<int> >&)': main.cpp:12:28: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i=0; i<graph.size(); ++i) seen[i] = 0; ~^~~~~~~~~~~~~ main.cpp:13:28: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i=0; i<graph.size(); ++i) ~^~~~~~~~~~~~~ main.cpp: In function 'bool operator<(const std::vector<int>&, const std::vector<int>&)': main.cpp:38:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i=0; i<v0.size(); ++i) ~^~~~~~~~~~