Compilare: user.cpp: In function ‘int main()’: user.cpp:28:27: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf (fin, "%d", &n); ^ user.cpp:31:63: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf (fin, "%lf %lf %lf", &C[i].x, &C[i].y, &C[i].r); ^ user.cpp:68:45: warning: ‘sol_c’ may be used uninitialized in this function [-Wmaybe-uninitialized] fout << sol_a << ' ' << sol_b << ' ' << sol_c << '\n'; ^