Compilare: user.cpp: In function ‘int main()’: user.cpp:65:28: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen(in, "r", stdin); ^ user.cpp:66:30: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen(out, "w", stdout); ^ user.cpp:69:26: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &N, &M); ^ user.cpp:75:24: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &X); ^ user.cpp:82:36: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d", &o, &a, &b); ^ user.cpp:87:49: warning: ‘root’ may be used uninitialized in this function [-Wmaybe-uninitialized] printf("%d\n", queryTree(root, a, b)); ^