Compilare: user.cpp: In function ‘void dfs(int)’: user.cpp:53:21: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < G[node].size(); i++) { ~~^~~~~~~~~~~~~~~~ user.cpp: In function ‘int main()’: user.cpp:142:25: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < Sol.size(); i++) ~~^~~~~~~~~~~~ user.cpp:147:25: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < Sol.size(); i++) ~~^~~~~~~~~~~~ user.cpp:149:33: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int j = i + 1; j < Sol.size(); j++) ~~^~~~~~~~~~~~ user.cpp: In constructor ‘InputReader::InputReader(const char*)’: user.cpp:15:42: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fread(buff,SIZE,1,input_file); ^ user.cpp: In member function ‘void InputReader::advance()’: user.cpp:40:46: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fread(buff,SIZE,1,input_file); ^