Submission #937720

#	Time	Username	Problem	Language	Result	Execution time	Memory
937720		zwezdinv	Modern Machine (JOI23_ho_t5)	C++17	26 / 100	3076 ms	9200 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 = k - 1; i >= 0; --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 (rl.empty()) {
                for (int i = k; i < c.size(); ++i) c[i] = 'B';
        } else if (lr.size() >= rl.size()) {
                int k = rl.size();
                int pos = lr[k - 1];
                for (int i = pos; i < c.size(); ++i) c[i] = 'B';
        } else {
                int k = lr.size();
                int pos = rl[k];
                for (int i = 0; i <= pos; ++i) c[i] = 'R';
        }
        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:9:31: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
    9 |         for (int i = k + 1; i < c.size(); ++i) {
      |                             ~~^~~~~~~~~~
Main.cpp:13:35: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   13 |                 for (int i = k; i < c.size(); ++i) c[i] = 'B';
      |                                 ~~^~~~~~~~~~
Main.cpp:17:37: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   17 |                 for (int i = pos; i < c.size(); ++i) c[i] = 'B';
      |                                   ~~^~~~~~~~~~

• Subtask 1: 3 / 3
• Subtask 2: 12 / 12
• Subtask 3: 0 / 10
• Subtask 4: 11 / 11
• Subtask 5: 0 / 26
• Subtask 6: 0 / 17
• Subtask 7: 0 / 21