Compilare: user.cpp: In function ‘int main()’: user.cpp:137:33: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen ("bile4.in", "r", stdin); ^ user.cpp:138:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen ("bile4.out", "w", stdout); ^ user.cpp:140:58: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf ("%d %d", &N, &M), nil = new nod (0, 0, 0, 0, 0, 0); ^ user.cpp:145:63: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf ("%d %d %d %d", &type, &st, &dr, &val), st ++, dr ++; ^