Borderou de evaluare (job #29497)

Compilare: user.cpp: In function 'int main()': user.cpp:17:40: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] user.cpp:18:42: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] user.cpp:20:28: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] user.cpp: In function 'int bt(long long int)': user.cpp:13:1: warning: control reaches end of non-void function [-Wreturn-type]