foo.cc: In function 'int main()':
foo.cc:8:12: warning: suggest parentheses around assignment used as truth value [-Wparentheses]
    8 |     while(C=C/10) B=B+C%10;
      |           ~^~~~~
foo.cc:4:12: warning: unused variable 'i' [-Wunused-variable]
    4 | {int A,B,C,i;
      |            ^
foo.cc:5:6: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
    5 | scanf("%d",&A);
      | ~~~~~^~~~~~~~~

[Hydro](https://hydro.ac)提供评测服务