Compilare: user.cpp: In function ‘void dfs(int, int)’: user.cpp:23:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0; i<gr[x].size(); ++i) ^ user.cpp:27:39: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j=0; j<gr[y].size(); ++j) ^ user.cpp:33:51: warning: operation on ‘nouy’ may be undefined [-Wsequence-point] noux=noux+nouy-(nouy=noux); ^ user.cpp: In function ‘int main()’: user.cpp:60:35: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j=0; j<gr[i].size(); ++j) ^ user.cpp:65:47: warning: operation on ‘nouy’ may be undefined [-Wsequence-point] noux=noux+nouy-(nouy=noux); ^