Submission #739729

#	Time	Username	Problem	Language	Result	Execution time	Memory
739729		danikoynov	Abracadabra (CEOI22_abracadabra)	C++14	100 / 100	1119 ms	132232 KiB

Main

/**
 ____ ____ ____ ____ ____ ____
||l |||e |||i |||n |||a |||d ||
||__|||__|||__|||__|||__|||__||
|/__\|/__\|/__\|/__\|/__\|/__\|

**/

#include<bits/stdc++.h>
#define endl '\n'

using namespace std;
typedef long long ll;

void speed()
{
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    cout.tie(NULL);
}

const int maxn = 2e5 + 10, maxq = 1e6 + 10;

int n, q, a[maxn], b[maxn], ans[maxq], nxt_pos[maxn], nxt_val[maxn];
vector < pair < int, int > > ask[maxn];

void shuffle_array()
{
    deque < int > d1, d2;
    for (int i = 1; i <= n / 2; i ++)
        d1.push_back(a[i]);
    for (int i = n / 2 + 1; i <= n; i ++)
        d2.push_back(a[i]);

    deque < int > res;
    while(!d1.empty() && !d2.empty())
    {
        if (d1.front() < d2.front())
        {
            res.push_back(d1.front());
            d1.pop_front();
        }
        else
        {
            res.push_back(d2.front());
            d2.pop_front();
        }
    }

    while(!d1.empty())
    {
        res.push_back(d1.front());
        d1.pop_front();
    }

    while(!d2.empty())
    {
        res.push_back(d2.front());
        d2.pop_front();
    }

    for (int i = 1; i <= n; i ++)
        a[i] = res[i - 1];
}

struct block
{
    int val, left, right;

    block(int _val = 0, int _left = 0, int _right = 0)
    {
        val = _val;
        left = _left;
        right = _right;
    }
    bool operator < (const block &bk) const
    {
        if (val == bk.val)
            return right < bk.right;

        return val < bk.val;
    }
};
set < block > act, blocks;
int fin[maxn], to, sz;

void shuffle_smart_init()
{

    while(true)
    {
        block cur = *act.rbegin();
        if (sz - (cur.right - cur.left + 1) + 1 > n / 2)
        {
            ///cout << "remove " << sz << " " << cur.left << " " << cur.right << endl;
            act.erase(cur);
            sz -= (cur.right - cur.left + 1);
        }
        else
        {
            break;
        }
    }

    if (sz == n / 2)
        return;
    /** for (block cur : act)
    {
     cout << "here " << cur.val << " " << cur.left << " " << cur.right << endl;
    }*/
    block cur = *act.rbegin();
    act.erase(cur);
    block fr = cur;
    fr.right = cur.right - (sz - n / 2);
    act.insert(fr);
    blocks.insert(fr);
    int idx = cur.right - (sz - n / 2) + 1, svd = idx;
    int sum_size = 0;
    //cout << idx << " : " << cur.right << endl;
    while(idx <= cur.right)
    {
        int gt = nxt_pos[idx];
        gt = min(gt, cur.right + 1);
        sum_size += (gt - idx);
        act.insert(block(a[idx], idx, gt - 1));
        blocks.insert(block(a[idx], idx, gt - 1));
        idx = gt;
    }
}

unordered_map < int, int > rev[maxn];
block bl[maxn * 2];
int tree[8 * maxn];
int bl_cnt;

void update(int root, int left, int right, int idx)
{
    if (left == right)
    {
        if (tree[root] == 0)
            tree[root] = bl[left].right - bl[left].left + 1;
        else
            tree[root] = 0;
        return;
    }

    int mid = (left + right) / 2;
    if (idx <= mid)
        update(root * 2, left, mid, idx);
    else
        update(root * 2 + 1, mid + 1, right, idx);

    tree[root] = tree[root * 2] + tree[root * 2 + 1];
}

int walk(int root, int left, int right, int k)
{
    if (left == right)
    {
        return a[bl[left].left + k - 1];
    }

    int mid = (left + right) / 2;
    if (tree[root * 2] >= k)
        return   walk(root * 2, left, mid, k);
    else
        return walk(root * 2 + 1, mid + 1, right, k - tree[root * 2]);
}


void shuffle_smart()
{

    while(true)
    {
        block cur = *act.rbegin();
        if (sz - (cur.right - cur.left + 1) + 1 > n / 2)
        {
            ///cout << "remove " << sz << " " << cur.left << " " << cur.right << endl;
            act.erase(cur);
            sz -= (cur.right - cur.left + 1);
        }
        else
        {
            break;
        }
    }

    if (sz == n / 2)
        return;
    /** for (block cur : act)
    {
     cout << "here " << cur.val << " " << cur.left << " " << cur.right << endl;
    }*/
    block cur = *act.rbegin();
    act.erase(cur);
    update(1, 1, bl_cnt, rev[cur.left][cur.right]);
    block fr = cur;
    fr.right = cur.right - (sz - n / 2);
    act.insert(fr);
    update(1, 1, bl_cnt, rev[fr.left][fr.right]);
    int idx = cur.right - (sz - n / 2) + 1, svd = idx;
    int sum_size = 0;
    //cout << idx << " : " << cur.right << endl;
    while(idx <= cur.right)
    {
        int gt = nxt_pos[idx];
        gt = min(gt, cur.right + 1);
        sum_size += (gt - idx);
        act.insert(block(a[idx], idx, gt - 1));
        update(1, 1, bl_cnt, rev[idx][gt - 1]);
        idx = gt;
    }
}
void solve()
{
    cin >> n >> q;
    for (int i = 1; i <= n; i ++)
    {
        cin >> a[i];
        b[i] = a[i];
    }

    int tp = 0;
    for (int i = 1; i <= q; i ++)
    {
        int t, v;
        cin >> t >> v;
        t = min(t, n);
        tp = t;
        if (t == 0)
            ans[i] = a[v];
        else
            ask[t].push_back({v, i});
    }

    shuffle_array();
    /**for (int i = 1; i <= n; i ++)
        cout << a[i] << " ";
    cout << endl;*/
    stack < int > st;
    for (int i = 1; i <= n; i ++)
    {
        while(!st.empty() && a[st.top()] < a[i])
        {
            nxt_pos[st.top()] = i;
            st.pop();
        }
        st.push(i);
    }
    while(!st.empty())
    {
        nxt_pos[st.top()] = n + 1;
        st.pop();
    }

    int i = 1;
    while(i <= n)
    {
        act.insert(block(a[i], i, nxt_pos[i] - 1));
        blocks.insert(block(a[i], i, nxt_pos[i] - 1));
        i = nxt_pos[i];
    }


    to = n;
    sz = n;

    for (int f = 1; f <= n; f ++)
    {
        shuffle_smart_init();
    }

    while(!act.empty())
    {
        block cur = *act.rbegin();    ///cout << to << " " << sz << " " << (cur.right - cur.left + 1) << endl;

        act.erase(cur);
        sz -= (cur.right - cur.left + 1);
    }

    for (block cur : blocks)
    {
        rev[cur.left][cur.right] = ++ bl_cnt;
        bl[bl_cnt] = cur;
        ///cout << cur.val << " " << cur.left << " " << cur.right << endl;
    }

    for (int i = 1; i <= n; i ++)
        a[i] = b[i];
    shuffle_array();

    i = 1;
    while(i <= n)
    {
        act.insert(block(a[i], i, nxt_pos[i] - 1));
                update(1, 1, bl_cnt, rev[i][nxt_pos[i] - 1]);
        ///blocks.insert(block(a[i], i, nxt_pos[i] - 1));
        i = nxt_pos[i];
    }


    to = n;
    sz = n;

    for (int f = 1; f <= n; f ++)
    {
        for (pair < int, int > cur : ask[f])
        {
            ans[cur.second] = walk(1, 1, bl_cnt, cur.first);
        }
        shuffle_smart();
    }


    for (int i = 1; i <= q; i ++)
        cout << ans[i] << endl;
}
int main()
{
    speed();
    solve();
    return 0;
}
/**
10 0
3 8 2 4 9 5 10 1 6 7
*/

Compilation message (stderr)

Main.cpp: In function 'void shuffle_smart_init()':
Main.cpp:117:45: warning: unused variable 'svd' [-Wunused-variable]
  117 |     int idx = cur.right - (sz - n / 2) + 1, svd = idx;
      |                                             ^~~
Main.cpp: In function 'void shuffle_smart()':
Main.cpp:202:45: warning: unused variable 'svd' [-Wunused-variable]
  202 |     int idx = cur.right - (sz - n / 2) + 1, svd = idx;
      |                                             ^~~
Main.cpp: In function 'void solve()':
Main.cpp:224:9: warning: variable 'tp' set but not used [-Wunused-but-set-variable]
  224 |     int tp = 0;
      |         ^~

• Subtask 1: 10 / 10
• Subtask 2: 40 / 40
• Subtask 3: 25 / 25
• Subtask 4: 25 / 25