Compilare: user.cpp: In function ‘int main()’: user.cpp:139:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("arbore3.in", "r", stdin); ^ user.cpp:140:39: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("arbore3.out", "w", stdout); ^ user.cpp: In function ‘void DFS(int, int)’: user.cpp:117:28: warning: array subscript is below array bounds [-Warray-bounds] if (buff[buff[i].next].key == X) { ^