sotron1.cpp: In function 'int main()': sotron1.cpp:14: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result sotron1.cpp:15: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result sotron1.cpp:17: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result sotron1.cpp:22: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result sotron1.cpp:16: warning: 'xs' may be used uninitialized in this function sotron1.cpp:16: warning: 'ys' may be used uninitialized in this function sotron1.cpp:16: warning: 'xf' may be used uninitialized in this function sotron1.cpp:16: warning: 'yf' may be used uninitialized in this function sotron1.cpp:16: warning: 'dir' may be used uninitialized in this function