Compilare: user.cpp: In function ‘bool isCyTree(int)’: user.cpp:51:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < V[nod].size() && (n2 == -1); ++ i) ~~^~~~~~~~~~~~~~~ user.cpp: In function ‘int main()’: user.cpp:86:20: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &t); ^ user.cpp:90:30: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &n, &m); ^ user.cpp:96:34: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &x, &y); ^