foo.cc: In function 'int main()':
foo.cc:8:12: warning: format '%d' expects a matching 'int' argument [-Wformat=]
    8 | printf("%.1d");
      |         ~~~^
      |            |
      |            int
foo.cc:5:9: warning: variable 'b' set but not used [-Wunused-but-set-variable]
    5 | float a,b;
      |         ^

[Hydro](https://hydro.ac)提供评测服务