foo.cc: In function 'int main()':
foo.cc:31:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(int i=1;i<=n;++i){
              ~^~~
foo.cc:43:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(int i=1;i<=tot;++i){
              ~^~~~~
foo.cc:44:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   for(int j=1;j<=cnt;++j){
               ~^~~~~
foo.cc:45:17: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
    for(int k=1;k<=n;++k){
                ~^~~

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

{"receive":"2020-08-10T00:36:26.605Z","handle":"2020-08-10T00:36:26.605Z","cache_start":"2020-08-10T00:36:26.616Z","read_cases":"2020-08-10T00:36:26.747Z","judge":"2020-08-10T00:36:26.753Z","done":"2020-08-10T00:36:27.239Z"}