foo.cc: In function 'void Dfs(long long int, long long int)':
foo.cc:25:35: warning: suggest parentheses around comparison in operand of '^' [-Wparentheses]
     if(temp[i]^temp[i+1]^temp[i+2]==0)
                          ~~~~~~~~~^~~
foo.cc:25:5: warning: this 'if' clause does not guard... [-Wmisleading-indentation]
     if(temp[i]^temp[i+1]^temp[i+2]==0)
     ^~
foo.cc:27:6: note: ...this statement, but the latter is misleadingly indented as if it were guarded by the 'if'
      return;
      ^~~~~~

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