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 = 0; i < v.size(); i++) v[i].clear();
        bool no_ans = false;
        for (int i = 0; i < s.length(); i++)
        {
            if (s[i] == '1')
            {
                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() - 1); }
                auto be = y.begin(); 
                int tmp = *be;
                y.erase(be);
                v[tmp].push_back(i);
                x.insert(tmp);
            }
        }
        for (int i = 0; i < v.size(); i++)
        {
            if (v[i].size() && s[v[i].back()] == '1') no_ans = true;
        }
        if (no_ans) cout << -1 << endl;
        else 
        {
            cout << v.size() << endl;
            for (int i = 0; i < v.size(); i++)
            {
                cout << v[i].size() << " ";
                for (int j = 0; j < v[i].size(); j++)
                {
                    cout << v[i][j] + 1 << " ";
                }
                cout << endl;
            }
        }
    }
    return 0;
}