Compilare: user.cpp: In function ‘int main()’: user.cpp:16:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=1;i<=c;i++) ^ user.cpp:23:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=1;i<=n;i++) ^ user.cpp:39:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<v[t1].size();i++) ^ user.cpp:13:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("carti3.in","r",stdin); ^ user.cpp:14:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("carti3.out","w",stdout); ^ user.cpp:36:12: warning: ‘cnt’ may be used uninitialized in this function [-Wmaybe-uninitialized] t1=(cnt+1)%2; ^