Submission #1355266

#TimeUsernameProblemLanguageResultExecution timeMemory
1355266enigma27Selling RNA Strands (JOI16_selling_rna)C++20
0 / 100
0 ms344 KiB

#include<bits/stdc++.h>
#define int         int64_t
constexpr int MOD = 1e9 + 7;
const int MAX_NODES = 2000006;
const int MAX_N = 100005;
constexpr int CHAR = 4;
using namespace std;

int N, M;
int pref_trie[MAX_NODES][4], suff_trie[MAX_NODES][4];
int pref_L[MAX_NODES], pref_R[MAX_NODES], suff_L[MAX_NODES], suff_R[MAX_NODES];
int pref_ptr = 1, suff_ptr = 1, timer_p = 0, timer_s = 0;

pair<int, int> points[MAX_N];

map<char, int> char_ind = {{'A', 0}, {'C', 1}, {'G', 2}, {'U', 3}};

int insert(int trie[][4], string &s, int &ptr) {
    int node = 0;
    for (char c : s) {
        int v = char_ind[c];
        if (trie[node][v] == 0) trie[node][v] = ptr++;
        node = trie[node][v];
    }
    return node;
}

void dfs(int u, int trie[][4], int L[], int R[], int &timer) {
    L[u] = ++timer;
    for (int i = 0; i < 4; i++) {
        if (trie[u][i] != 0) dfs(trie[u][i], trie, L, R, timer);
    }
    R[u] = timer;
}

int get_node(int trie[][4], string &s) {
    int node = 0;
    for (char c : s) {
        int v = char_ind[c];
        if (trie[node][v] == 0) return -1;
        node = trie[node][v];
    }
    return node;
}

struct QueryEvent {
    int x, y1, y2, id, weight;
};

int bit[MAX_NODES];
void update(int idx, int val) {
    for (; idx < MAX_NODES; idx += idx & -idx) bit[idx] += val;
}
int query_bit(int idx) {
    int res = 0;
    for (; idx > 0; idx -= idx & -idx) res += bit[idx];
    return res;
}

int ans[MAX_N];

void solve() {
    cin >> N >> M;

    vector<string> S(N);
    for (int i = 0; i < N; i++) {
        cin >> S[i];
        int u = insert(pref_trie, S[i], pref_ptr);
        reverse(S[i].begin(), S[i].end());
        int v = insert(suff_trie, S[i], suff_ptr);
        points[i] = {u, v};
    }

    dfs(0, pref_trie, pref_L, pref_R, timer_p);
    dfs(0, suff_trie, suff_L, suff_R, timer_s);

    vector<pair<int, int>> coords;
    for (int i = 0; i < N; i++) {
        coords.emplace_back(pref_L[points[i].first], suff_L[points[i].second]);
    }
    sort(coords.begin(), coords.end());

    vector<QueryEvent> events;
    for (int i = 0; i < M; i++) {
        string P, Q;
        cin >> P >> Q;
        reverse(Q.begin(), Q.end());

        int node_p = get_node(pref_trie, P);
        int node_q = get_node(suff_trie, Q);

        if (node_p != -1 && node_q != -1) {
            int x1 = pref_L[node_p], x2 = pref_R[node_p];
            int y1 = suff_L[node_q], y2 = suff_R[node_q];
            events.push_back({x1 - 1, y1, y2, i, -1});
            events.push_back({x2, y1, y2, i, 1});
        }
    }
    sort(events.begin(), events.end(), [](QueryEvent a, QueryEvent b) {
        return a.x < b.x;
    });

    int pt = 0;
    for (auto &e : events) {
        while (pt < N && coords[pt].first <= e.x) {
            update(coords[pt].second, 1);
            pt++;
        }
        ans[e.id] += e.weight * (query_bit(e.y2) - query_bit(e.y1 - 1));
    }

    for (int i = 0; i < M; i++) cout << ans[i] << "\n";
}
signed main() {
    auto begin = std::chrono::high_resolution_clock::now();
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);
#ifndef ONLINE_JUDGE
    freopen("input.txt", "r", stdin);
    freopen("output.txt", "w", stdout);
#endif

    int test = 1;
    //cin>>test;
    while (test--) {
        solve();
    }
    auto end = std::chrono::high_resolution_clock::now();
    auto elapsed = std::chrono::duration_cast<std::chrono::nanoseconds>(end - begin);
    cerr << "Time measured: " << static_cast<double>(elapsed.count()) * 1e-9 << " seconds.\n";
    return 0;
}

Compilation message (stderr)

selling_rna.cpp: In function 'int main()':
selling_rna.cpp:120:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  120 |     freopen("input.txt", "r", stdin);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
selling_rna.cpp:121:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  121 |     freopen("output.txt", "w", stdout);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~
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