Compilare: user.cpp: In function ‘void bf()’: user.cpp:23:25: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<G[k].size();i++) ^ user.cpp:12:10: warning: unused variable ‘j’ [-Wunused-variable] int i,k,j,g=1; ^ user.cpp:18:16: warning: unused variable ‘kk’ [-Wunused-variable] long long p=0,kk=n*m; ^ user.cpp: In function ‘int main()’: user.cpp:43:40: 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); ^ user.cpp:44:42: 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); ^ user.cpp:45:24: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&n,&m); ^ user.cpp:47:36: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d",&x,&y,&cost); ^