Submission #937703

#	Time	Username	Problem	Language	Result	Execution time	Memory
937703		zwezdinv	Modern Machine (JOI23_ho_t5)	C++17	Compilation error	0 ms	0 KiB

Main

#include <bits/stdc++.h>

std::string process(std::string c, int k) {
        // c[k] = 'R';
        // std::vector<int> lr, rl;
        // for (int i = 0; i < k; ++i) {
        //         if (c[i] == 'R') lr.push_back(i);
        // }
        // for (int i = k + 1; i < c.size(); ++i) {
        //         if (c[i] == 'B') rl.push_back(i);
        // }
        // if (lr.size() >= rl.size()) {
        //         int k = rl.size();
        //         int pos = lr[lr.size() - k];
        //         for (int i = pos; i < c.size(); ++i) c[i] = 'B';
        // } else {
        //         int k = lr.size();
        //         int pos = rl[k - 1];
        //         for (int i = 0; i <= pos; ++i) c[i] = 'R';
        // }
        // return c;
        c[k] = 'R';
        while (0 <= k && k < n) {
                if (c[k] == 'R') {
                        c[k] = 'B';
                        k++;
                } else {
                        c[k] = 'R';
                        k--;
                }
        }
        return c;
}

int main() {
        std::cin.tie(nullptr)->sync_with_stdio(false);

        int n, m;
        std::cin >> n >> m;
        std::string c;
        std::cin >> c;
        std::vector<int> a(m);
        for (auto& i : a) std::cin >> i, --i;
        if (n <= 10) {
                int st = 0;
                for (int i = 0; i < n; ++i) {
                        st |= (c[i] == 'R') << i;
                }
                std::vector<std::vector<int>> ss(1 << n, std::vector<int>(n));
                for (int mask = 0; mask < 1 << n; ++mask) {
                        for (int i = 0; i < n; ++i) {
                                int m4sk = mask;
                                int ptr = i;
                                m4sk |= 1 << i;
                                while (0 <= ptr && ptr < n) {
                                        m4sk ^= 1 << ptr;
                                        if (~m4sk >> ptr & 1) {
                                                ptr++;
                                        } else {
                                                ptr--;
                                        }
                                }
                                ss[mask][i] = m4sk;
                        }
                }
                std::vector<int> qq(1 << n, -1);
                std::vector<int> pos(m, -1);
                std::vector<int> leader(m, -1);
                std::vector<std::vector<std::pair<int, int>>> que(m);
                int q;
                std::cin >> q;
                std::vector<int> ans(q);
                for (int i = 0; i < q; ++i) {
                        int l, r;
                        std::cin >> l >> r;
                        --l, --r;
                        que[r].emplace_back(l, i);
                }
                auto get = [&](int u) -> int {
                        while (u != leader[u]) u = leader[u] = leader[leader[u]];
                        return u;
                }; 
                for (int i = 0; i < m; ++i) {
                        if (qq[st] == -1) {
                                qq[st] = i;
                                pos[i] = st;
                                leader[i] = i;
                        } else {
                                leader[i] = qq[st];
                        }
                        std::vector<int> nw(1 << n, -1);
                        for (int j = 0; j < 1 << n; ++j) {
                                if (qq[j] == -1) continue;
                                int k = ss[j][a[i]];
                                if (nw[k] != -1) {
                                        leader[qq[j]] = nw[k];
                                } else {
                                        nw[k] = qq[j];
                                        pos[qq[j]] = k;
                                }
                        }
                        qq = nw;
                        for (auto [l, id] : que[i]) {
                                ans[id] = __builtin_popcount(pos[get(l)]);
                        }
                }
                for (auto i : ans) std::cout << i << '\n';
        } else {
                int q;
                std::cin >> q;
                int l, r;
                std::cin >> l >> r;
                --l, --r;
                for (int i = l; i <= r; ++i) {
                        c = process(c, a[i]);
                }
                std::cout << std::count(c.begin(), c.end(), 'R');
        }
}

Compilation message (stderr)

Main.cpp: In function 'std::string process(std::string, int)':
Main.cpp:23:30: error: 'n' was not declared in this scope
   23 |         while (0 <= k && k < n) {
      |                              ^