Compilare: main.cpp: In function 'void bellman()': main.cpp:25:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int it=0; it<v[nod].size(); it++){ ~~^~~~~~~~~~~~~~ main.cpp: In function 'int main()': main.cpp:42:37: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("bellmanford.in","r",stdin); ^ main.cpp:43:39: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("bellmanford.out","w",stdout); ^