zoo.cpp: In function 'void read()': zoo.cpp:27: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result zoo.cpp:28: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result zoo.cpp:31: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result zoo.cpp: In function 'void compute()': zoo.cpp:226: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result zoo.cpp:228: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result zoo.cpp:231: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result