foo.cc: In function 'long long int read()':
foo.cc:8:22: warning: suggest parentheses around '&&' within '||' [-Wparentheses]
     while ((ch!='-') && ch<'0' || ch>'9')
            ~~~~~~~~~~^~~~~~~~~
foo.cc: In function 'int main()':
foo.cc:44:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d%d",&n,&m);
  ~~~~~^~~~~~~~~~~~~~

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

正在同步测试数据，请稍后
{"receive":"2020-08-10T04:23:45.294Z","handle":"2020-08-10T04:23:45.294Z","cache_start":"2020-08-10T04:23:45.302Z","read_cases":"2020-08-10T04:23:45.939Z","judge":"2020-08-10T04:23:45.940Z","done":"2020-08-10T04:23:47.143Z"}