Submission #479846

#	Time	Username	Problem	Language	Result	Execution time	Memory
479846		alextodoran	Financial Report (JOI21_financial)	C++17	100 / 100	430 ms	29668 KiB

Main

/**
 ____ ____ ____ ____ ____
||a |||t |||o |||d |||o ||
||__|||__|||__|||__|||__||
|/__\|/__\|/__\|/__\|/__\|

**/

#include <bits/stdc++.h>

using namespace std;

typedef long long ll;

const int N_MAX = 300000;

int N, D;

int A[N_MAX + 2];

struct DSUNode
{
    int root;
    int l, r;
};

DSUNode DSU[N_MAX + 2];

void init ()
{
    for(int u = 1; u <= N; u++)
    {
        DSU[u].root = u;
        DSU[u].l = u;
        DSU[u].r = u;
    }
}

int findRoot (int u)
{
    if(DSU[u].root == u)
        return u;
    return DSU[u].root = findRoot(DSU[u].root);
}

void join (int u, int v)
{
    u = findRoot(u);
    v = findRoot(v);
    if(u == v)
        return;
    DSU[v].l = DSU[u].l;
    DSU[u].root = v;
}

bool active[N_MAX + 2];

void activate (int u)
{
    active[u] = true;
    if(active[u - 1] == true)
        join(u - 1, u);
    if(active[u + 1] == true)
        join(u, u + 1);
}

int order[N_MAX + 2];

int leftBound[N_MAX + 2];

int SGT[N_MAX * 4 + 2];

void update (int node, int l, int r, int upos, int uval)
{
    if(l == r)
    {
        SGT[node] = uval;
        return;
    }

    int mid = (l + r) / 2;
    int lSon = node * 2, rSon = node * 2 + 1;

    if(upos <= mid)
        update(lSon, l, mid, upos, uval);
    if(mid + 1 <= upos)
        update(rSon, mid + 1, r, upos, uval);

    SGT[node] = max(SGT[lSon], SGT[rSon]);
}
void update (int upos, int uval)
{
    update(1, 1, N, upos, uval);
}

int query (int node, int l, int r, int ql, int qr)
{
    if(ql <= l && r <= qr)
        return SGT[node];

    int mid = (l + r) / 2;
    int lSon = node * 2, rSon = node * 2 + 1;

    int answer = 0;
    if(ql <= mid)
        answer = max(answer, query(lSon, l, mid, ql, qr));
    if(mid + 1 <= qr)
        answer = max(answer, query(rSon, mid + 1, r, ql, qr));
    return answer;
}
int query (int ql, int qr)
{
    if(ql > qr)
        return 0;
    return query(1, 1, N, ql, qr);
}

int maxRec[N_MAX + 2];

int main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(0);
    cout.tie(0);

    cin >> N >> D;
    for(int i = 1; i <= N; i++)
        cin >> A[i];

    for(int k = 1; k <= N; k++)
        order[k] = k;

    {
        sort(order + 1, order + N + 1, [&] (const int &i, const int &j)
             {
                 return make_pair(A[i], i) > make_pair(A[j], j);
             });

        set <int> s;
        init();

        for(int k = 1; k <= N; k++)
        {
            int i = order[k];

            set <int> :: iterator it = s.upper_bound(i);
            if(it == s.begin())
                leftBound[i] = 1;
            else
                leftBound[i] = (*prev(it) - D + 1);

            activate(i);
            int root = findRoot(i);
            if(DSU[root].r - DSU[root].l + 1 >= D)
                s.insert(DSU[root].r);
        }
    }

    {
        sort(order + 1, order + N + 1, [&] (const int &i, const int &j)
             {
                 return make_pair(A[i], N - i) < make_pair(A[j], N - j);
             });

        for(int k = 1; k <= N; k++)
        {
            int i = order[k];
            maxRec[i] = query(leftBound[i], i - 1) + 1;
            update(i, maxRec[i]);
        }

        cout << query(1, N) << "\n";
    }

    return 0;
}

• Subtask 1: 14 / 14
• Subtask 2: 14 / 14
• Subtask 3: 20 / 20
• Subtask 4: 12 / 12
• Subtask 5: 5 / 5
• Subtask 6: 35 / 35