Compilare: main.cpp: In function 'void dfs(int)': main.cpp:34:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0 ; i < g[node].size() ; i++) ~~^~~~~~~~~~~~~~~~ main.cpp: In function 'int main()': main.cpp:120:17: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] FastIO , FILES; ^ main.cpp:120:17: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]