Compilare: user.cpp: In function ‘void dfs(int)’: user.cpp:87: warning: comparison between signed and unsigned integer expressions user.cpp: In function ‘void dfs2(int)’: user.cpp:96: warning: comparison between signed and unsigned integer expressions user.cpp: In function ‘int main()’: user.cpp:129: warning: comparison between signed and unsigned integer expressions user.cpp:130: warning: comparison between signed and unsigned integer expressions user.cpp:103: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result user.cpp:104: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result user.cpp:107: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result user.cpp:110: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result