foo.cc: In function 'void solve()':
foo.cc:57:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(int i = 0; i < s.size(); i++) idx[s[i]] = i;
                 ~~^~~~~~~~~~
foo.cc:58:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(int i = 0; i < r0.size(); i++) {
                 ~~^~~~~~~~~~~

自豪的采用jd5进行评测(github.com/masnn/jd5)

{"receive":"2020-02-16T07:02:47.396Z","handle":"2020-02-16T07:02:47.396Z","done":"2020-02-16T07:02:48.642Z"}