foo.cc: In function 'int erfen(double)':
foo.cc:13:12: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   int mid=L+R>>1;
           ~^~
foo.cc: In function 'int main()':
foo.cc:24:24: warning: format '%lld' expects argument of type 'long long int*', but argument 2 has type 'int*' [-Wformat=]
  scanf("%lld%lld",&n,&s);
                   ~~   ^
foo.cc:24:24: warning: format '%lld' expects argument of type 'long long int*', but argument 3 has type 'int*' [-Wformat=]
foo.cc:26:25: warning: format '%lld' expects argument of type 'long long int*', but argument 2 has type 'int*' [-Wformat=]
   scanf("%lld%lld",&x,&y);
                    ~~   ^
foo.cc:26:25: warning: format '%lld' expects argument of type 'long long int*', but argument 3 has type 'int*' [-Wformat=]
foo.cc:36:20: warning: format '%lld' expects argument of type 'long long int', but argument 2 has type 'int' [-Wformat=]
  printf("%lld",f[n]);
                ~~~~^
foo.cc:24:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%lld%lld",&n,&s);
  ~~~~~^~~~~~~~~~~~~~~~~~
foo.cc:26:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%lld%lld",&x,&y);
   ~~~~~^~~~~~~~~~~~~~~~~~

自豪的采用 HydroJudge 进行评测(github.com/hydro-dev/HydroJudge)

{"receive":"2020-07-10T06:05:55.880Z","handle":"2020-07-10T06:05:55.880Z","cache_start":"2020-07-10T06:05:55.888Z","read_cases":"2020-07-10T06:05:56.027Z","judge":"2020-07-10T06:05:56.027Z","done":"2020-07-10T06:05:57.248Z"}