ratb.cpp: In function 'int main()': ratb.cpp:5: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result ratb.cpp:6: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result ratb.cpp:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result ratb.cpp:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result ratb.cpp:7: warning: 'a' may be used uninitialized in this function ratb.cpp:7: warning: 'b' may be used uninitialized in this function ratb.cpp:7: warning: 'a1' may be used uninitialized in this function ratb.cpp:7: warning: 'b1' may be used uninitialized in this function