Compilare: user.cpp: In function ‘int main()’: user.cpp:39:10: warning: statement has no effect [-Wunused-value] for(l; l>0; l/=2) ^ user.cpp:36:33: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("proc.in","r",stdin); ^ user.cpp:37:31: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d %d",&n,&k,&p); ^ user.cpp:48:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("proc.out","w",stdout); ^