foo.cc: In function 'int main()':
foo.cc:48:4: warning: this 'if' clause does not guard... [-Wmisleading-indentation]
    if (vis[i]) continue; vis[i] = 1;
    ^~
foo.cc:48:26: note: ...this statement, but the latter is misleadingly indented as if it were guarded by the 'if'
    if (vis[i]) continue; vis[i] = 1;
                          ^~~

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