Submission #498565

#	Time	Username	Problem	Language	Result	Execution time	Memory
498565		khoabright	Financial Report (JOI21_financial)	C++17	100 / 100	425 ms	25228 KiB

Main

//problem: https://oj.uz/problem/view/JOI21_financial
//solution: https://codeforces.com/blog/entry/91295

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

#define ll long long
#define pii pair<int, int>
#define ff first
#define ss second
#define pb push_back
#define rep(i, a, b) for (int i = (int)a; i <= (int)b; ++i)
#define rep1(i, a, b) for (int i = (int)a; i >= (int)b; --i)
#define all(x) x.begin(), x.end()

struct segtree {
    int sz = 1;
    vector<int> maxi;

    void init(int SIZE) {
        while (sz < SIZE) sz *= 2;
        maxi.resize(2 * sz);
    }

    void update(int i, int v, int x, int lx, int rx) {
        if (rx - lx == 1) {
            maxi[x] = v;
            return;
        }

        int m = (lx + rx) >> 1;
        if (i < m) update(i, v, 2 * x + 1, lx, m);
        else update(i, v, 2 * x + 2, m, rx);
        maxi[x] = max(maxi[2 * x + 1], maxi[2 * x + 2]);
    }
    void update(int i, int v) {update(i, v, 0, 0, sz);}

    int query(int l, int r, int x, int lx, int rx) {
        if (rx <= l || r <= lx) return 0;
        if (l <= lx && rx <= r) return maxi[x];
        int m = (lx + rx) >> 1;
        return max(query(l, r, 2 * x + 1, lx, m), query(l, r, 2 * x + 2, m, rx));
    }
    int query(int l, int r) {return query(l, r, 0, 0, sz);}
};

bool cmp(pii x, pii y) {
    return make_pair(x.ff, -x.ss) < make_pair(y.ff, -y.ss);
}

const int N = 3e5 + 5;
int pa[N];

int fp(int u) {
    if (u == pa[u]) return u;
    return pa[u] = fp(pa[u]);
}

void join(int x, int y) {
    x = fp(x), y = fp(y);
    if (x == y) return;
    if (x < y) swap(x, y);
    pa[x] = y;
    return;
}

void solve() {
    int n, d; cin >> n >> d;
    rep(i, 1, n) pa[i] = i;
    vector<pii> a(n + 1);
    rep(i, 1, n) cin >> a[i].ff, a[i].ss = i;

    sort(a.begin() + 1, a.end(), cmp);

    segtree st;
    st.init(n + 1);
    st.update(0, 5);
    set<int> pos;

    int ans = 0;
    rep(i, 1, n) {
        auto it = pos.lower_bound(a[i].ss);
        if (it != pos.end()) {
            int id = *it;
            if (abs(id - a[i].ss) <= d) join(a[i].ss, id);
        }
        if (it != pos.begin()) {
            --it;
            int id = *it;
            if (abs(id - a[i].ss) <= d) join(a[i].ss, id);
        }

        int left = fp(a[i].ss);
        int tmp = st.query(left, a[i].ss) + 1;
        st.update(a[i].ss, tmp);
        ans = max(ans, tmp);
        pos.insert(a[i].ss);
    }
    cout << ans;
}

int main() {
    ios_base::sync_with_stdio(0); cin.tie(0);
    solve();
}

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