Compilare: user.cpp: In function ‘int main()’: user.cpp:41:13: warning: unused variable ‘re’ [-Wunused-variable] int i,k,re,st,dr,mi,la,nr,lan,m,cm; ^ user.cpp:39:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("farey.in","r",stdin); ^ user.cpp:40:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("farey.out","w",stdout); ^ user.cpp:42:24: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&n,&k); ^ user.cpp:66:4: warning: ‘lan’ may be used uninitialized in this function [-Wmaybe-uninitialized] k=k-lan; ^ user.cpp:41:25: warning: ‘la’ may be used uninitialized in this function [-Wmaybe-uninitialized] int i,k,re,st,dr,mi,la,nr,lan,m,cm; ^