Compilare: user.cpp: In function ‘void dfs(long int)’: user.cpp:34:35: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(long i=0;i<list[nod].size();i++){ ^ user.cpp: In function ‘void Euler(long int)’: user.cpp:42:30: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<list[nod].size();i++){ ^ user.cpp: In function ‘int main()’: user.cpp:95:30: warning: format ‘%ld’ expects argument of type ‘long int’, but argument 2 has type ‘std::vector<std::vector<long int> >::size_type {aka unsigned int}’ [-Wformat=] printf("%ld\n",ans.size()); ^ user.cpp:96:24: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<ans.size();i++){ ^ user.cpp:97:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(j=0;j<ans[i].size();j++) printf("%ld ",ans[i][j]); ^ user.cpp:57:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("johnie.in","r",stdin); ^ user.cpp:58:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("johnie.out","w",stdout); ^ user.cpp:60:27: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%ld %ld",&n,&m); ^ user.cpp:62:31: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%ld %ld",&x,&y); ^