foo.cc:50:21: error: empty character constant
    if (str[t[i]] == '') {RES = "0"; break;}
                     ^~
foo.cc: In function 'int main()':
foo.cc:20:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
             for (int i = 0; i < t.length(); i++) vis[t[i]] = true;
                             ~~^~~~~~~~~~~~
foo.cc:20:58: warning: array subscript has type 'char' [-Wchar-subscripts]
             for (int i = 0; i < t.length(); i++) vis[t[i]] = true;
                                                          ^
foo.cc:21:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
             for (int i = 0; i < s.length(); i++) vis[s[i]] = true;
                             ~~^~~~~~~~~~~~
foo.cc:21:58: warning: array subscript has type 'char' [-Wchar-subscripts]
             for (int i = 0; i < s.length(); i++) vis[s[i]] = true;
                                                          ^
foo.cc:22:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
             for (int i = 0; i < min(t.length(), s.length()); i++)
                             ~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
foo.cc:24:27: warning: array subscript has type 'char' [-Wchar-subscripts]
                     p[t[i]].push_back(s[i]);
                           ^
foo.cc:25:29: warning: array subscript has type 'char' [-Wchar-subscripts]
                     out[t[i]]++;
                             ^
foo.cc:26:28: warning: array subscript has type 'char' [-Wchar-subscripts]
                     in[s[i]]++;
                            ^
foo.cc:40:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
         for (int i = 0; i < p[x].size(); i++) {
                         ~~^~~~~~~~~~~~~
foo.cc:45:13: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     if (cnt >= t.length()) {
         ~~~~^~~~~~~~~~~~~
foo.cc:46:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
         for (int i = 0; i < ans.length(); i++)
                         ~~^~~~~~~~~~~~~~
foo.cc:49:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
         for (int i = 0; i < t.length(); i++)
                         ~~^~~~~~~~~~~~

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