checkin.cpp: In function 'int main()': checkin.cpp:51: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result checkin.cpp:52: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result checkin.cpp:54: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result checkin.cpp:56: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result checkin.cpp:61: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result checkin.cpp: In function 'int bsL(int, int)': checkin.cpp:37: warning: 'last' may be used uninitialized in this function