c073: 00101 - The Blocks Problem

#include<iostream>
#include<vector>
#include<algorithm>
#define endl '\n'
using namespace std;
int main() {
    cin.tie(nullptr);
    ios::sync_with_stdio(false);
    int n, a, b;
    string str1, str2;
    while (cin >> n) {
        vector<pair<size_t, size_t>> p(n);
        vector<vector<int>> v(n);
        for (int i = 0; i != n; i++)
            v[i].assign({i}), p[i] = {i, 0};
        while (cin >> str1) {
            if (str1 == "quit") break;
            cin >> a >> str2 >> b;
            if (a == b || p[a].first == p[b].first) continue;
            auto pb = [&](auto pos) {
                auto x = p[pos].first, y = p[pos].second + 1;
                vector<int> tmp(v[x].begin() + y, v[x].end());
                v[x].erase(v[x].begin() + y, v[x].end());
                for (const auto& i : tmp)
                    v[i].emplace_back(i), p[i] = {i, v[i].size() - 1};
            };
            if (str1 == "move") pb(a);
            if (str2 == "onto") pb(b);
            auto x = p[a].first, y = p[a].second;
            vector<int> tmp(v[x].begin() + y, v[x].end());
            v[x].erase(v[x].begin() + y, v[x].end());
            x = p[b].first;
            for (const auto& i : tmp)
                v[x].emplace_back(i), p[i] = {x, v[x].size() - 1};
        }
        for (size_t i = 0; i < v.size(); i++) {
            cout << i << ": ";
            for (const auto& j : v[i])
                cout << j << ' ';
            cout << endl;
        }
    }
    return 0;
}