cabana.cpp: In function 'int main()': cabana.cpp:62: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result cabana.cpp:63: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result cabana.cpp:68: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result cabana.cpp:71: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result cabana.cpp:65: warning: 'y2' may be used uninitialized in this function