Compilare: user.cpp: In function ‘void prec(int)’: user.cpp:21:37: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < V[nod].size(); ++ i) ^ user.cpp: In function ‘void dfs(int, long long int)’: user.cpp:33:37: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < V[nod].size(); ++ i) ^ user.cpp:39:37: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < V[nod].size(); ++ i) ^ user.cpp: In function ‘int main()’: user.cpp:57:26: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &n, &h); ^ user.cpp:61:36: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d", &x, &y, &c); ^