Compilare: main.cpp: In function 'int common(int, int)': main.cpp:26:14: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while (i1<g[a].size() && i2<g[b].size()) ~~^~~~~~~~~~~~ main.cpp:26:32: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while (i1<g[a].size() && i2<g[b].size()) ~~^~~~~~~~~~~~ main.cpp:42:1: warning: no return statement in function returning non-void [-Wreturn-type] } ^ main.cpp: In function 'void solve(int)': main.cpp:59:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i=0;i<g[q.front().second].size();++i) ~^~~~~~~~~~~~~~~~~~~~~~~~~~~ main.cpp: In function 'int main()': main.cpp:83:32: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("fof.in","r",stdin); ^ main.cpp:84:34: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("fof.out","w",stdout); ^