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Submission #898455

# Submission time Handle Problem Language Result Execution time Memory
898455 2024-01-04T16:49:46 Z GrandTiger1729 Joker (BOI20_joker) C++17
25 / 100
 401 ms 12236 KB 
#include <bits/stdc++.h>
using namespace std;

struct DSU
{
    vector<int> rt, sz;
    vector<int> stk;
    DSU(int n)
    {
        rt.resize(n);
        iota(rt.begin(), rt.end(), 0);
        sz.resize(n, 1);
    }
    int find(int u)
    {
        if (u == rt[u])
        {
            return u;
        }
        return find(rt[u]);
    }
    bool same(int u, int v)
    {
        return find(u) == find(v);
    }
    void unite(int u, int v)
    {
        u = find(u), v = find(v);
        if (u == v)
        {
            stk.push_back(-1);
            return;
        }
        if (sz[u] > sz[v])
        {
            swap(u, v);
        }
        rt[u] = v;
        sz[v] += sz[u];
        stk.push_back(u);
    }
    void undo()
    {
        int u = stk.back();
        stk.pop_back();
        if (u == -1)
        {
            return;
        }
        int v = rt[u];
        sz[v] -= sz[u];
        rt[u] = u;
    }
};

const int B = 21, C = 450, D = 21;
int main()
{
    cin.tie(0)->sync_with_stdio(0);
    int n, m, q;
    cin >> n >> m >> q;
    vector<pair<int, int>> ed(m);
    for (int i = 0; i < m; i++)
    {
        int u, v;
        cin >> u >> v;
        u--, v--;
        ed[i] = make_pair(u, v);
    }
    vector<int> rr(m, -1);
    for (int c = 0; c * C * B < m; c++)
    {
        int L1 = c * C * B, L2 = min(m, (c + 1) * C * B);
        int R = -1;
        DSU dsu(2 * n);
        {
            for (int i = 0; i < L1; i++)
            {
                auto [u, v] = ed[i];
                dsu.unite(u, v + n);
                dsu.unite(u + n, v);
                if (dsu.same(u, v))
                {
                    R = i;
                    break;
                }
            }
            if (R != -1)
            {
                break;
            }
            for (int i = L1; i < L2; i++)
            {
                auto [u, v] = ed[i];
                dsu.unite(u, v + n);
                dsu.unite(u + n, v);
                if (dsu.same(u, v))
                {
                    R = i;
                    break;
                }
            }
            if (R == -1)
            {
                R = m - 1;
                while (R >= L2)
                {
                    auto [u, v] = ed[R];
                    dsu.unite(u, v + n);
                    dsu.unite(u + n, v);
                    if (dsu.same(u, v))
                    {
                        dsu.undo();
                        dsu.undo();
                        break;
                    }
                    R--;
                }
                for (int i = m - 1; i > R; i--)
                {
                    dsu.undo();
                    dsu.undo();
                }
                for (int i = L1; i < L2; i++)
                {
                    dsu.undo();
                    dsu.undo();
                }
            }
            else
            {
                for (int i = L1; i <= R; i++)
                {
                    dsu.undo();
                    dsu.undo();
                }
                R = m - 1;
            }
            for (int i = m - 1; i > R; i--)
            {
                auto [u, v] = ed[i];
                dsu.unite(u, v + n);
                dsu.unite(u + n, v);
            }
        }
        for (int d = (L2 - 1 - L1) / (B * D); d >= 0; d--)
        {
            int ll1 = L1 + d * B * D, ll2 = min(L2, ll1 + B * D);
            int r2 = -1;
            for (int i = L1; i < ll1; i++)
            {
                auto [u, v] = ed[i];
                dsu.unite(u, v + n);
                dsu.unite(u + n, v);
                if (dsu.same(u, v))
                {
                    r2 = i;
                    break;
                }
            }
            if (r2 != -1)
            {
                for (int i = L1; i <= r2; i++)
                {
                    dsu.undo();
                    dsu.undo();
                }
                continue;
            }
            for (int i = ll1; i < ll2; i++)
            {
                auto [u, v] = ed[i];
                dsu.unite(u, v + n);
                dsu.unite(u + n, v);
            }
            r2 = R;
            for (int b = (ll2 - 1 - ll1) / B; b >= 0; b--)
            {
                int l1 = ll1 + b * B, l2 = min(ll2, l1 + B);
                for (int i = l1; i < l2; i++)
                {
                    dsu.undo();
                    dsu.undo();
                }
                for (int i = R; i > r2; i--)
                {
                    auto [u, v] = ed[i];
                    dsu.unite(u, v + n);
                    dsu.unite(u + n, v);
                }
                int r = r2;
                bool f = 0;
                for (int i = r; i >= l1; i--)
                {
                    int l = l1;
                    while (l < l2 && l <= i)
                    {
                        auto [u, v] = ed[l];
                        dsu.unite(u, v + n);
                        dsu.unite(u + n, v);
                        if (dsu.same(u, v))
                        {
                            break;
                        }
                        l++;
                    }
                    rr[i] = max(rr[i], l);
                    l = min(l, l2 - 1);
                    l = min(l, i);
                    for (int j = l1; j <= l; j++)
                    {
                        dsu.undo();
                        dsu.undo();
                    }
                    auto [u, v] = ed[i];
                    dsu.unite(u, v + n);
                    dsu.unite(u + n, v);
                    if (dsu.same(u, v))
                    {
                        r2 = i;
                        f = 1;
                        break;
                    }
                }
                if (!f)
                {
                    r2 = l1;
                }
                for (int i = r2; i <= R; i++)
                {
                    dsu.undo();
                    dsu.undo();
                }
            }
            for (int i = L1; i < ll1; i++)
            {
                dsu.undo();
                dsu.undo();
            }
            for (int i = r2 + 1; i <= R; i++)
            {
                auto [u, v] = ed[i];
                dsu.unite(u, v + n);
                dsu.unite(u + n, v);
            }
            R = r2;
        }
    }
    while (q--)
    {
        int l, r;
        cin >> l >> r;
        l--, r--;
        cout << (rr[r] >= l ? "NO" : "YES") << '\n';
    }
    return 0;
}

Subtask #1
0 / 6.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 348 KB Output is correct
2 Correct 0 ms 348 KB Output is correct
3 Correct 0 ms 344 KB Output is correct
4 Correct 0 ms 348 KB Output is correct
5 Correct 0 ms 348 KB Output is correct
6 Correct 0 ms 348 KB Output is correct
7 Correct 0 ms 348 KB Output is correct
8 Incorrect 1 ms 348 KB Output isn't correct
9 Halted 0 ms 0 KB -

Subtask #2
0 / 8.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 348 KB Output is correct
2 Correct 0 ms 348 KB Output is correct
3 Correct 0 ms 344 KB Output is correct
4 Correct 0 ms 348 KB Output is correct
5 Correct 0 ms 348 KB Output is correct
6 Correct 0 ms 348 KB Output is correct
7 Correct 0 ms 348 KB Output is correct
8 Incorrect 1 ms 348 KB Output isn't correct
9 Halted 0 ms 0 KB -

Subtask #3
25.0 / 25.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 348 KB Output is correct
2 Correct 0 ms 348 KB Output is correct
3 Correct 174 ms 6392 KB Output is correct
4 Correct 401 ms 12236 KB Output is correct
5 Correct 200 ms 11604 KB Output is correct
6 Correct 132 ms 8920 KB Output is correct
7 Correct 138 ms 8852 KB Output is correct
8 Correct 197 ms 7944 KB Output is correct
9 Correct 199 ms 8728 KB Output is correct
10 Correct 248 ms 10436 KB Output is correct
11 Correct 190 ms 9024 KB Output is correct
12 Correct 218 ms 10140 KB Output is correct
13 Correct 181 ms 7636 KB Output is correct
14 Correct 196 ms 8424 KB Output is correct
15 Correct 234 ms 9456 KB Output is correct
16 Correct 237 ms 10408 KB Output is correct

Subtask #4
0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 348 KB Output is correct
2 Correct 0 ms 348 KB Output is correct
3 Correct 0 ms 344 KB Output is correct
4 Correct 0 ms 348 KB Output is correct
5 Correct 0 ms 348 KB Output is correct
6 Correct 0 ms 348 KB Output is correct
7 Correct 0 ms 348 KB Output is correct
8 Incorrect 1 ms 348 KB Output isn't correct
9 Halted 0 ms 0 KB -

Subtask #5
0 / 22.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 348 KB Output is correct
2 Correct 0 ms 348 KB Output is correct
3 Correct 0 ms 344 KB Output is correct
4 Correct 0 ms 348 KB Output is correct
5 Correct 0 ms 348 KB Output is correct
6 Correct 0 ms 348 KB Output is correct
7 Correct 0 ms 348 KB Output is correct
8 Incorrect 1 ms 348 KB Output isn't correct
9 Halted 0 ms 0 KB -

Subtask #6
0 / 29.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 348 KB Output is correct
2 Correct 0 ms 348 KB Output is correct
3 Correct 0 ms 344 KB Output is correct
4 Correct 0 ms 348 KB Output is correct
5 Correct 0 ms 348 KB Output is correct
6 Correct 0 ms 348 KB Output is correct
7 Correct 0 ms 348 KB Output is correct
8 Incorrect 1 ms 348 KB Output isn't correct
9 Halted 0 ms 0 KB -