Compilare: user.cpp: In function ‘void dfs(long int)’: user.cpp:24:36: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(long i=0;i<list[node].size();i++){ ^ user.cpp: In function ‘void dfs2(long int)’: user.cpp:34:37: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(long i=0;i<rlist[node].size();i++){ ^ user.cpp: In function ‘int main()’: user.cpp:78:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<mb.size();i++){ ^ user.cpp:84:30: warning: format ‘%ld’ expects argument of type ‘long int’, but argument 2 has type ‘std::vector<std::pair<long int, long int> >::size_type {aka unsigned int}’ [-Wformat=] printf("%ld\n",ans.size()); ^ user.cpp:85:24: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<ans.size();i++) printf("%ld %ld\n",ans[i].xx,ans[i].yy); ^ user.cpp:57:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("tarnacop.in","r",stdin); ^ user.cpp:58:39: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("tarnacop.out","w",stdout); ^ user.cpp:60:38: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%ld%ld%ld%ld",&n,&m,&s,&d); ^ user.cpp:62:42: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%ld%ld%ld%ld",&x,&y,&C,&I); if(C==0) continue; ^