Compilare: user.cpp: In function ‘void read_input()’: user.cpp:14: warning: unused variable ‘j’ user.cpp:14: warning: unused variable ‘k’ user.cpp:16: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result user.cpp:18: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result user.cpp:19: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result user.cpp: In function ‘int checkAll(long int)’: user.cpp:57: warning: unused variable ‘j’ user.cpp:57: warning: unused variable ‘k’ user.cpp: In function ‘int main()’: user.cpp:72: warning: unused variable ‘j’ user.cpp:74: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result user.cpp:101: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result