Compilare: user.cpp: In function ‘int BS()’: user.cpp:53: warning: unused variable ‘mid’ user.cpp: In function ‘int main()’: user.cpp:71: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result user.cpp:72: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result user.cpp:74: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result user.cpp:77: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result user.cpp: In function ‘int BS()’: user.cpp:67: warning: control reaches end of non-void function user.cpp:53: warning: ‘ans’ may be used uninitialized in this function