dir.cpp: In function 'int main()': dir.cpp:27: warning: comparison between signed and unsigned integer expressions dir.cpp:62: warning: comparison between signed and unsigned integer expressions dir.cpp:25: warning: unused variable 'n' dir.cpp:25: warning: unused variable 'x' dir.cpp:23: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result dir.cpp:24: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result