turn1.cpp: In function 'void dfs(int)': turn1.cpp:21: warning: comparison between signed and unsigned integer expressions turn1.cpp: In function 'int main()': turn1.cpp:33: warning: comparison between signed and unsigned integer expressions turn1.cpp:27: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result turn1.cpp:28: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result turn1.cpp:29: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result turn1.cpp:31: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result