foo.cc: In function 'int main()':
foo.cc:16:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
         for(int i=2;i<a.size();i++){
                     ~^~~~~~~~~

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":"2020-07-09T12:32:12.077Z","handle":"2020-07-09T12:32:12.077Z","cache_start":"2020-07-09T12:32:12.086Z","read_cases":"2020-07-09T12:32:12.505Z","judge":"2020-07-09T12:32:12.506Z","done":"2020-07-09T12:32:13.616Z"}