ocr.cpp: In function 'int main()': ocr.cpp:47: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result ocr.cpp:48: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result ocr.cpp:52: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result ocr.cpp:55: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result ocr.cpp:49: warning: 'imin' may be used uninitialized in this function ocr.cpp:49: warning: 'jmin' may be used uninitialized in this function