Compilare: main.cpp: In function 'void solve()': main.cpp:23:39: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0; i<v[nod].size(); i++){ ~^~~~~~~~~~~~~~ main.cpp:33:39: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0; i<v[n].size(); i++){ ~^~~~~~~~~~~~ main.cpp: In function 'int main()': main.cpp:52:40: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("maxflow.in","r",stdin); ^ main.cpp:53:44: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("maxflow.out", "w", stdout); ^