Compilare: user.cpp: In function ‘int main()’: user.cpp:40:23: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(in, "%d", &t); ^ user.cpp:44:31: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(in, "%d%d", &n, &m); ^ user.cpp:46:33: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(in, "%d%d", &x, &y); ^ user.cpp:53:5: warning: ‘l’ may be used uninitialized in this function [-Wmaybe-uninitialized] while((1 << k) < r) ^