Compilare: user.cpp: In function ‘int main()’: user.cpp:9:21: warning: unused variable ‘r’ [-Wunused-variable] int t , n , k , r , ok; ^ user.cpp:9:25: warning: unused variable ‘ok’ [-Wunused-variable] int t , n , k , r , ok; ^ user.cpp:10:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("mere.in" , "r" ,stdin); ^ user.cpp:11:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("mere.out", "w" ,stdout); ^ user.cpp:12:21: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d\n",&t); ^ user.cpp:14:31: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d\n",&n,&k); ^