Compilare: main.cpp: In function 'int main()': main.cpp:39:21: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 1 ; i < adj[node].size() ; ++i) ~~^~~~~~~~~~~~~~~~~~ main.cpp:20:35: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("arb3.in" , "r" , stdin) ; ^ main.cpp:21:37: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("arb3.out" , "w" , stdout) ; ^