Submission #937818

#	Time	Username	Problem	Language	Result	Execution time	Memory
937818		_callmelucian	Matching (CEOI11_mat)	C++14	100 / 100	321 ms	57568 KiB

mat

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

typedef long long ll;
typedef long double ld;
typedef pair<ll,ll> pl;
typedef pair<int,int> pii;
typedef tuple<int,int,int> tt;

#define all(a) a.begin(), a.end()
#define filter(a) a.erase(unique(all(a)), a.end())

struct BIT {
    vector<int> tr;
    BIT (int sz) : tr(sz + 1, INT_MIN) {}

    int p (int k) { return k & -k; }

    void update (int k, int val) {
        for (; k < tr.size(); k += p(k)) tr[k] = max(tr[k], val);
    }

    int query (int k, int ans = INT_MIN) {
        for (; k; k -= p(k)) ans = max(ans, tr[k]);
        return ans;
    }
};

int main()
{
    ios::sync_with_stdio(0);
    cin.tie(0);

    int n, m; cin >> n >> m;
    vector<int> pos(n + 1), s(n), h(m);
    for (int i = 1; i <= n; i++) {
        cin >> pos[i];
        s[--pos[i]] = i;
    }
    for (int i = 0; i < m; i++) cin >> h[i];

    s.push_back(INT_MAX);
    for (int u : h) s.push_back(u);

    vector<int> lower(n), upper(n), pi(n + m + 1), ans;
    BIT lw(n + 1), up(n + 1);
    for (int i = 0; i < n; i++) {
        int lb = lw.query(s[i]), ub = up.query(n - s[i] + 1);
        lower[i] = (lb == INT_MIN ? -1 : i - pos[lb]);
        upper[i] = (ub == INT_MIN ? -1 : i - pos[-ub]);
        lw.update(s[i], s[i]);
        up.update(n - s[i] + 1, -s[i]);
    }

    function<bool(int,int)> ok = [&] (int j, int i) {
        if (max(s[j], s[i]) == INT_MAX) return 0;
        if (lower[j] != -1)
            if (s[i - lower[j]] > s[i]) return 0;
        if (upper[j] != -1)
            if (s[i - upper[j]] < s[i]) return 0;
        return 1;
    };

    for (int i = 1; i < n + m + 1; i++) {
        int j = pi[i - 1];
        while (j && !ok(j, i)) j = pi[j - 1];
        if (ok(j, i)) pi[i] = j + 1;

        if (pi[i] == n) ans.push_back(i - 2 * n + 1);
    }

    cout << ans.size() << "\n";
    for (int u : ans) cout << u << " ";

    return 0;
}

Compilation message (stderr)

mat.cpp: In member function 'void BIT::update(int, int)':
mat.cpp:20:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   20 |         for (; k < tr.size(); k += p(k)) tr[k] = max(tr[k], val);
      |                ~~^~~~~~~~~~~

• Subtask 1: 9 / 9
• Subtask 2: 9 / 9
• Subtask 3: 9 / 9
• Subtask 4: 9 / 9
• Subtask 5: 9 / 9
• Subtask 6: 9 / 9
• Subtask 7: 9 / 9
• Subtask 8: 9 / 9
• Subtask 9: 8 / 8
• Subtask 10: 10 / 10
• Subtask 11: 10 / 10