Submission #151878

#	Time	Username	Problem	Language	Result	Execution time	Memory
151878		forestryks	Matching (CEOI11_mat)	C++14	100 / 100	1426 ms	48216 KiB

mat

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

using ll = long long;
using ld = long double;
using pii = pair<int, int>;
#define rep(i, n) for (int (i) = 0; (i) < (n); ++(i))
#define all(x) (x).begin(), (x).end()
#define FAST_IO ios_base::sync_with_stdio(false); cin.tie(0); cout.tie(0);
#define f first
#define s second

const int MAXN = 1e6 + 5;
int m, n;
int p[MAXN];
int a[MAXN * 2];
int up[MAXN];
int down[MAXN];
int pf[MAXN * 2];
int t[MAXN * 4];

void update(int v, int tl, int tr, int p, int x) {
    if (tr - tl == 1) {
        t[v] += x;
        return;
    }

    int tm = tl + (tr - tl) / 2;
    if (p < tm) {
        update(v * 2 + 1, tl, tm, p, x);
    } else {
        update(v * 2 + 2, tm, tr, p, x);
    }
    t[v] = t[v * 2 + 1] + t[v * 2 + 2];
    // t[p] += x;
}

int find_last(int v, int tl, int tr, int l, int r) {
    if (r <= tl || tr <= l) return -1;
    int tm = tl + (tr - tl) / 2;
    if (l <= tl && tr <= r) {
        if (t[v] == 0) return -1;
        if (tr - tl == 1) return tl;
        if (t[v * 2 + 2] != 0) return find_last(v * 2 + 2, tm, tr, l, r);
        return find_last(v * 2 + 1, tl, tm, l, r);
    }

    int res = find_last(v * 2 + 2, tm, tr, l, r);
    if (res == -1) res = find_last(v * 2 + 1, tl, tm, l, r);
    return res;
    // for (int i = r - 1; i >= l; --i) {
    //     if (t[i]) return i;
    // }
    // return -1;
}

int find_first(int v, int tl, int tr, int l, int r) {
    if (r <= tl || tr <= l) return -1;
    int tm = tl + (tr - tl) / 2;
    if (l <= tl && tr <= r) {
        if (t[v] == 0) return -1;
        if (tr - tl == 1) return tl;
        if (t[v * 2 + 1] != 0) return find_first(v * 2 + 1, tl, tm, l, r);
        return find_first(v * 2 + 2, tm, tr, l, r);
    }

    int res = find_first(v * 2 + 1, tl, tm, l, r);
    if (res == -1) res = find_first(v * 2 + 2, tm, tr, l, r);
    return res;
    // for (int i = l; i < r; ++i) {
    //     if (t[i]) return i;
    // }
    // return -1;
}

void calc() {
    fill(up, up + m, -1);
    fill(down, down + m, -1);

    rep(i, m) {
        update(0, 0, m, a[i], 1);
    }

    for (int i = m - 1; i >= 0; --i) {
        update(0, 0, m, a[i], -1);
        up[i] = find_first(0, 0, m, a[i], m);
        down[i] = find_last(0, 0, m, 0, a[i]);
    }

    rep(i, m) {
        if (up[i] != -1) up[i] = p[up[i]];
        if (down[i] != -1) down[i] = p[down[i]];
    }

    // for (int i = 0; i < m; ++i) {
    //     auto it = s.lower_bound({a[i], 0});
    //     if (it != s.end()) {
    //         up[i] = it->s;
    //     }
    //     if (it != s.begin()) {
    //         down[i] = prev(it)->s;
    //     }
    //     s.insert({a[i], i});
    // }
}

int main() {
    FAST_IO;
    cin >> m >> n;
    rep(i, m) {
        cin >> p[i];
        p[i]--;
    }
    rep(i, m) {
        a[p[i]] = i;
    }
    a[m] = -1;
    rep(i, n) {
        cin >> a[m + 1 + i];
    }

    calc();

    pf[0] = 0;
    for (int i = 1; i < n + m + 1; ++i) {
        if (i == m) {
            pf[i] = 0;
            continue;
        }
        int j = pf[i - 1];
        while (j > 0) {
            if (j == m) {
                j = pf[j - 1];
                continue;
            }

            int u = up[j];
            int d = down[j];

            if ((d != -1 && a[i - j + d] > a[i]) || (u != -1 && a[i - j + u] < a[i])) {
                j = pf[j - 1];
                continue;
            }

            pf[i] = j + 1;
            break;
        }

        if (j == 0) pf[i] = 1;
    }

    // rep(i, n + m + 1) {
    //     cout << a[i] << ' ';
    // }
    // cout << endl;

    // rep(i, m) {
    //     cout << down[i] << ' ';
    // }
    // cout << endl;

    // rep(i, m) {
    //     cout << up[i] << ' ';
    // }
    // cout << endl;

    // rep(i, n + m + 1) {
    //     cout << pf[i] << ' ';
    // }
    // cout << endl;

    vector<int> ans;
    for (int i = m + 1 + m - 1; i < n + m + 1; ++i) {
        if (pf[i] == m) {
            ans.push_back(i - m + 1 - m - 1);
        }
    }

    cout << ans.size() << endl;
    for (auto it : ans) {
        cout << it + 1 << ' ';
    }
    cout << endl;
}

• 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