CF949A/950C Zebras

思路：

贪心乱搞。

实现：

 #include <bits/stdc++.h>
 using namespace std;
 vector<vector<int>> v;
 int main()
 {
     string s;
     while (cin >> s)
     {
         set<int> x, y;
         for (int i = ; i < v.size(); i++) v[i].clear();
         bool no_ans = false;
         for (int i = ; i < s.length(); i++)
         {
             if (s[i] == '')
             {
                 if (x.empty()) { no_ans = true; break; }
                 auto be = x.begin();
                 int tmp = *be;
                 x.erase(be);
                 v[tmp].push_back(i);
                 y.insert(tmp);
             }
             else
             {
                 if (y.empty()) { v.push_back(vector<int>()); y.insert(v.size() - ); }
                 auto be = y.begin();
                 int tmp = *be;
                 y.erase(be);
                 v[tmp].push_back(i);
                 x.insert(tmp);
             }
         }
         for (int i = ; i < v.size(); i++)
         {
             if (v[i].size() && s[v[i].back()] == '') no_ans = true;
         }
         if (no_ans) cout << - << endl;
         else
         {
             cout << v.size() << endl;
             for (int i = ; i < v.size(); i++)
             {
                 cout << v[i].size() << " ";
                 for (int j = ; j < v[i].size(); j++)
                 {
                     cout << v[i][j] +  << " ";
                 }
                 cout << endl;
             }
         }
     }
     return ;
 }