cmmmc.cpp: In function 'void f()': cmmmc.cpp:7: warning: unused variable 'j' cmmmc.cpp:7: warning: unused variable 'k' cmmmc.cpp:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result cmmmc.cpp: In function 'int main()': cmmmc.cpp:68: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result cmmmc.cpp:69: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result cmmmc.cpp:71: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result cmmmc.cpp: In function 'void f()': cmmmc.cpp:7: warning: 'sa' may be used uninitialized in this function cmmmc.cpp:7: warning: 'sb' may be used uninitialized in this function