Compilare: user.cpp: In function ‘int main()’: user.cpp:18:18: warning: unused variable ‘j’ [-Wunused-variable] int n, m, i, j, x, y, c, s = 0; ^ user.cpp:18:27: warning: unused variable ‘c’ [-Wunused-variable] int n, m, i, j, x, y, c, s = 0; ^ user.cpp: In function ‘void dfs(int)’: user.cpp:49:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for( i = 0; i < v[x].size(); ++i ) ^ user.cpp: In function ‘int main()’: user.cpp:15:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("grarb.in","r",stdin); ^ user.cpp:16:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("grarb.out","w",stdout); ^ user.cpp:20:24: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&n,&m); ^ user.cpp:23:28: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&x,&y); ^