Compilare: user.cpp: In function ‘void dfs(long int)’: user.cpp:87:33: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<Tree[node].Q.size();i++){ ^ user.cpp:91:36: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<Tree[node].list.size();i++) ^ user.cpp: In function ‘int main()’: user.cpp:99:33: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("undo.in","r",stdin); ^ user.cpp:100:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("undo.out","w",stdout); ^ user.cpp:102:27: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%ld %ld",&n,&m); ^ user.cpp:105:25: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%ld",&op); ^ user.cpp:107:42: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%ld %ld %ld",&x,&y,&z); ^ user.cpp:115:35: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%ld %ld",&x,&y); ^ user.cpp:118:28: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%ld",&x); ^