/in/foo.c: In function 'main':
/in/foo.c:5:17: warning: format '%f' expects argument of type 'float *', but argument 2 has type 'double *' [-Wformat=]
    5 |         scanf("%f", &f);
      |                ~^   ~~
      |                 |   |
      |                 |   double *
      |                 float *
      |                %lf