Compilare: user.cpp: In function ‘int main()’: user.cpp:6:49: warning: variable ‘cate’ set but not used [-Wunused-but-set-variable] int a1,b1,n,m,i,k,vfc,vfl,lin,cst,cdr,j1,j2,cate,l,vfsusc,vfsusl,vfjosc,vfjosl,vfdrl,vfdrc,vfstl,vfstc,pp; ^ user.cpp:7:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("marmote.in","r",stdin); ^ user.cpp:8:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("marmote.out","w",stdout); ^ user.cpp:9:34: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d%d",&n,&m,&k,&l); ^ user.cpp:12:30: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&a1,&b1); ^