sediu.cpp: In function 'void dfs(int)': sediu.cpp:25: warning: comparison between signed and unsigned integer expressions sediu.cpp:20: warning: unused variable 'n' sediu.cpp: In function 'int main()': sediu.cpp:65: warning: comparison between signed and unsigned integer expressions sediu.cpp:49: warning: unused variable 'j' sediu.cpp:46: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result sediu.cpp:47: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result sediu.cpp:51: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result sediu.cpp:54: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result