radare.cpp: In function 'void DFS(int, int)': radare.cpp:16: warning: comparison between signed and unsigned integer expressions radare.cpp: In function 'int main()': radare.cpp:47: warning: unused variable 'j' radare.cpp:45: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result radare.cpp:46: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result radare.cpp:48: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result radare.cpp:50: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result radare.cpp:55: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result