Compilare: user.cpp: In function ‘void dfs(int)’: user.cpp:24:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0; i<vv[x].size(); ++i) ^ user.cpp: In function ‘int main()’: user.cpp:46:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("ninjago.in","r",stdin); ^ user.cpp:47:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("ninjago.out","w",stdout); ^ user.cpp:50:29: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d",&t,&n,&m); ^ user.cpp:53:65: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d %c%c%c%c\n",&v[i].x,&v[i].y,&c1,&c2,&c3,&c4); ^