Compilare: user.cpp: In function ‘int main()’: user.cpp:38:12: warning: unused variable ‘j’ [-Wunused-variable] int i, j, k, N; ^ user.cpp:38:15: warning: unused variable ‘k’ [-Wunused-variable] int i, j, k, N; ^ user.cpp:35:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen ("arbpal.in", "r", stdin); ^ user.cpp:36:40: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen ("arbpal.out", "w", stdout); ^ user.cpp:39:21: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf ("%d", &N); ^ user.cpp:42:33: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf ("%d%d", &x0, &y0); ^ user.cpp:47:17: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf ("\n"); ^ user.cpp:50:27: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf ("%c ", &ch); ^