Compilare: user.cpp: In function ‘void dfs(int, int)’: user.cpp:21:45: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int alpha = 0; alpha < order.size (); alpha ++) ^ user.cpp:26:47: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int beta = 0; beta < order.size (); beta ++) ^ user.cpp: In function ‘int main()’: user.cpp:63:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen ("camion2.in", "r", stdin); ^ user.cpp:64:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen ("camion2.out", "w", stdout); ^ user.cpp:66:24: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf ("%d %d", &N, &P); ^ user.cpp:70:35: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf ("%d %d %d", &x, &y, &z); ^