Compilare: user.cpp: In function ‘void dfs(int)’: user.cpp:28:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i=0;i<g[x].size();++i) ^ user.cpp: In function ‘void load()’: user.cpp:15:32: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%lld %lld", &n, &m); ^ user.cpp:18:36: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%lld %lld", &x,&y); ^ user.cpp: In function ‘int main()’: user.cpp:36:32: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("dfs.in","r",stdin); ^ user.cpp:37:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("dfs.out","w",stdout); ^