Compilare: user.cpp: In function ‘int main()’: user.cpp:31:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen ("scmax.in", "r", stdin); ^ user.cpp:32:39: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen ("scmax.out", "w", stdout); ^ user.cpp:34:23: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf ("%d\n", &n); ^ user.cpp:38:28: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf ("%d", &v[i]); ^ user.cpp:65:5: warning: ‘p1’ may be used uninitialized in this function [-Wmaybe-uninitialized] for (int i = p1; i; i = prv[i]) ^