Infant Care Rooms

#include <bits/stdc++.h>
using namespace std;

bool check(string a, string b) {
    return a[0] == b[0] || a[1] == b[1];
}

int main()
{
    int n;
    cin >> n;
    vector<stack<string>> v(n);
    for (int i = 0; i < n; ++i) {
        string s;
        cin >> s;
        v[i].push(s);
    }

    for (int i = 0; i < v.size(); ++i) {
        while (i < v.size() && v[i].empty())
            v.erase(v.begin()+i);
        if (i >= v.size()) break;
        if (i-3 >= 0 && check(v[i-3].top(), v[i].top())) {
            v[i-3].push(v[i].top());
            v[i].pop();
            i = i-4;
        } else if (i-1 >= 0 && check(v[i-1].top(), v[i].top())) {
            v[i-1].push(v[i].top());
            v[i].pop();
            i = i-2;
        }
    }

    printf("%d\n", v.size());
    for (int i = 0; i < v.size(); ++i)
        printf("%d ", v[i].size());

    return 0;
}