/in/foo.c: In function 'main':
/in/foo.c:5:9: warning: format '%f' expects argument of type 'float *', but argument 2 has type 'double *' [-Wformat=]
    5 | scanf("%f%f", &a, &b); // 读取两个整数
      |        ~^     ~~
      |         |     |
      |         |     double *
      |         float *
      |        %lf
/in/foo.c:5:11: warning: format '%f' expects argument of type 'float *', but argument 3 has type 'double *' [-Wformat=]
    5 | scanf("%f%f", &a, &b); // 读取两个整数
      |          ~^       ~~
      |           |       |
      |           float * double *
      |          %lf