foo.cc: In function 'int main()':
foo.cc:58:14: error: 'f' was not declared in this scope
   58 |         ans+=f[W][i];
      |              ^
foo.cc:42:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   42 |     scanf("%d",&T);
      |     ~~~~~^~~~~~~~~
foo.cc:45:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   45 |         scanf("%d%d%d",&K,&W,&n);
      |         ~~~~~^~~~~~~~~~~~~~~~~~~
foo.cc:49:18: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   49 |             scanf("%d",&v[i]);
      |             ~~~~~^~~~~~~~~~~~
foo.cc:53:18: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   53 |             scanf("%d",&w[i]);
      |             ~~~~~^~~~~~~~~~~~

[Hydro](https://hydro.ac)提供评测服务