Compilare: user.cpp: In function ‘void dynamics(int)’: user.cpp:28:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i=0;i<v.size();i++) ^ user.cpp:31:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (l=1;l<v.size();l++) { ^ user.cpp:32:30: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i=0,j=l;j<v.size();i++,j++) { ^ user.cpp: In function ‘void dfs(int, int)’: user.cpp:47:28: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i=0;i<f[nod].size();i++) ^ user.cpp:52:28: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i=0;i<f[nod].size();i++) ^ user.cpp:46:11: warning: unused variable ‘j’ [-Wunused-variable] int i,j; ^ user.cpp: In function ‘int main()’: user.cpp:83:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("petsoft.in","r",stdin); ^ user.cpp:84:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("petsoft.out","w",stdout); ^ user.cpp:85:19: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&n); ^ user.cpp:87:23: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&j); ^