Submission #1060892

#	Time	Username	Problem	Language	Result	Execution time	Memory
1060892		becaido	Radio Towers (IOI22_towers)	C++17	17 / 100	4091 ms	75556 KiB

towers

#pragma GCC optimize("O3,unroll-loops")
#pragma GCC target("avx,popcnt,sse4,abm")
#include <bits/stdc++.h>
using namespace std;

#ifndef WAIMAI
#include "towers.h"
#else
#include "stub.cpp"
#endif

#ifdef WAIMAI
#define debug(HEHE...) cout << "[" << #HEHE << "] : ", dout(HEHE)
void dout() {cout << '\n';}
template<typename T, typename...U>
void dout(T t, U...u) {cout << t << (sizeof...(u) ? ", " : ""), dout(u...);}
#else
#define debug(...) 7122
#endif

#define ll long long
#define Waimai ios::sync_with_stdio(false), cin.tie(0)
#define FOR(x,a,b) for (int x = a, I = b; x <= I; x++)
#define pb emplace_back
#define F first
#define S second

#define lpos pos*2
#define rpos pos*2+1

const int INF = 2e9 + 1;
const int SIZE = 1e5 + 5;

int n;
int a[SIZE], ty[SIZE];

struct Segtree {
    struct T {
        int mx, mn, ld, rd;
        T operator + (const T &o) const {
            T re;
            re.mx = max(mx, o.mx);
            re.mn = min(mn, o.mn);
            re.ld = max({ld, o.ld, o.mx - mn});
            re.rd = max({rd, o.rd, mx - o.mn});
            return re;
        }
    } node[SIZE << 2];

    void build(int pos, int l, int r) {
        if (l == r) {
            node[pos].mx = node[pos].mn = a[l];
            return;
        }
        int mid = (l + r) / 2;
        build(lpos, l, mid);
        build(rpos, mid + 1, r);
        node[pos] = node[lpos] + node[rpos];
    }
    int schl(int pos, int l, int r, int L, int R, int x) {
        if (l == L && r == R) {
            if (node[pos].mx < x) return 0;
            if (l == r) return l;
            int mid = (L + R) / 2, re = schl(lpos, l, mid, L, mid, x);
            return re == 0 ? schl(rpos, mid + 1, r, mid + 1, R, x) : re;
        }
        int mid = (L + R) / 2, re;
        if (r <= mid) return schl(lpos, l, r, L, mid, x);
        if (l > mid) return schl(rpos, l, r, mid + 1, R, x);
        re = schl(lpos, l, mid, L, mid, x);
        return re == 0 ? schl(rpos, mid + 1, r, mid + 1, R, x) : re;
    }
    int schr(int pos, int l, int r, int L, int R, int x) {
        if (l == L && r == R) {
            if (node[pos].mx < x) return 0;
            if (l == r) return l;
            int mid = (L + R) / 2, re = schr(rpos, mid + 1, r, mid + 1, R, x);
            return re == 0 ? schr(lpos, l, mid, L, mid, x) : re;
        }
        int mid = (L + R) / 2, re;
        if (r <= mid) return schr(lpos, l, r, L, mid, x);
        if (l > mid) return schr(rpos, l, r, mid + 1, R, x);
        re = schr(rpos, mid + 1, r, mid + 1, R, x);
        return re == 0 ? schr(lpos, l, mid, L, mid, x) : re;
    }
    T que(int pos, int l, int r, int L, int R) {
        if (l == L && r == R) return node[pos];
        int mid = (L + R) / 2;
        if (r <= mid) return que(lpos, l, r, L, mid);
        if (l > mid) return que(rpos, l, r, mid + 1, R);
        return que(lpos, l, mid, L, mid) + que(rpos, mid + 1, r, mid + 1, R);
    }
} tree;

struct Node {
    int cnt, pcnt, ls, rs;
} node[2 * SIZE * (__lg(SIZE) + 3)];

int sz, root;
vector<pair<int, int>> vroot;
void upd(int &pos, int l, int r, int p, int t, int x) {
    node[++sz] = node[pos];
    pos = sz;
    (t == 1 ? node[pos].cnt : node[pos].pcnt) += x;
    if (l == r) return;
    int mid = (l + r) / 2;
    if (p <= mid) upd(node[pos].ls, l, mid, p, t, x);
    else upd(node[pos].rs, mid + 1, r, p, t, x);
}
int que(int pos, int l, int r, int L, int R, int t) {
    if (l == L && r == R) return t == 1 ? node[pos].cnt : node[pos].pcnt;
    int mid = (L + R) / 2;
    if (r <= mid) return que(node[pos].ls, l, r, L, mid, t);
    if (l > mid) return que(node[pos].rs, l, r, mid + 1, R, t);
    return que(node[pos].ls, l, mid, L, mid, t) + que(node[pos].rs, mid + 1, r, mid + 1, R, t);
}
int sch(int pos, int l, int r, int t, int k) {
    int tot = (t ? node[pos].cnt : node[pos].pcnt);
    if (k > tot) return 0;
    if (l == r) return l;
    int mid = (l + r) / 2, ltot = (t ? node[node[pos].ls].cnt : node[node[pos].ls].pcnt);
    return k <= ltot ? sch(node[pos].ls, l, mid, t, k) : sch(node[pos].rs, mid + 1, r, t, k - ltot);
}

void init(int N, vector<int> H) {
    n = N;
    if (n == 1) return;
    FOR (i, 1, n) a[i] = H[i - 1];
    FOR (i, 1, n) {
        if ((i == 1 || a[i] < a[i - 1]) && (i == n || a[i] < a[i + 1])) ty[i] = 1;
        if ((i == 1 || a[i] > a[i - 1]) && (i == n || a[i] > a[i + 1])) ty[i] = 2;
    }

    set<int> s;
    multiset<pair<int, int>> ms;
    for (int i = 1, x = 1; i <= n; i++) if (ty[i] == x) {
        s.insert(i);
        x ^= 3;
    }
    if (ty[*s.rbegin()] == 2) s.erase(*s.rbegin());
    a[0] = a[n + 1] = INF;
    s.insert(0), s.insert(n + 1);
    bool f = 0;
    for (auto it = s.begin(); it != s.end(); it++) {
        f ^= 1;
        if (f == 0) continue;
        int i = *it;
        if (it != s.begin()) {
            int l = *prev(it);
            ms.emplace(a[i] - a[l], i);
        }
        if (next(it) != s.end()) {
            int r = *next(it);
            ms.emplace(a[i] - a[r], i);
        }
    }
    for (int i : s) if (ty[i]) upd(root, 1, n, i, ty[i], 1);
    vroot.pb(0, root);
    while (s.size() > 3) {
        int d = ms.begin()->F;
        while (ms.size() && ms.begin()->F == d) {
            auto [_, i] = *ms.begin();
            auto it = s.lower_bound(i), lit = prev(it), rit = next(it);
            int l = *lit, r = *rit;
            int il = *prev(lit), ir = *next(rit);
            if (a[l] > a[r]) {
                ms.erase(ms.find({a[i] - a[l], i}));
                ms.erase(ms.find({a[il] - a[l], il}));
                if (a[i] < a[il]) {
                    ms.erase({a[i] - a[r], i});
                    ms.emplace(a[il] - a[r], il);
                    s.erase(i), upd(root, 1, n, i, 2, -1);
                } else {
                    int j = *prev(s.find(il));
                    ms.erase(ms.find({a[il] - a[j], il}));
                    ms.emplace(a[i] - a[j], i);
                    s.erase(il), upd(root, 1, n, il, 2, -1);
                }
                s.erase(l), upd(root, 1, n, l, 1, -1);
            } else {
                ms.erase(ms.find({a[i] - a[r], i}));
                ms.erase(ms.find({a[ir] - a[r], ir}));
                if (a[i] < a[ir]) {
                    ms.erase({a[i] - a[l], i});
                    ms.emplace(a[ir] - a[l], ir);
                    s.erase(i), upd(root, 1, n, i, 2, -1);
                } else {
                    int j = *next(s.find(ir));
                    ms.erase(ms.find({a[ir] - a[j], ir}));
                    ms.emplace(a[i] - a[j], i);
                    s.erase(ir), upd(root, 1, n, ir, 2, -1);
                }
                s.erase(r), upd(root, 1, n, r, 1, -1);
            }
        }
        vroot.pb(d + 1, root);
    }
    tree.build(1, 1, n);
}

int max_towers(int L, int R, int D) {
    L++, R++;
    if (L == R) return 1;
    root = (lower_bound(vroot.begin(), vroot.end(), make_pair(D + 1, 0)) - 1)->S;
    int ans = que(root, L, R, 1, n, 1);
    if (ans == 0) {
        int pcnt = que(root, L, R, 1, n, 2);
        if (pcnt == 0) return 1;
        int i = sch(root, 1, n, 2, L == 1 ? 1 : que(root, 1, L - 1, 1, n, 2) + 1);
        return 1 + (tree.que(1, L, i, 1, n).mn + D <= a[i] && tree.que(1, i, R, 1, n).mn + D <= a[i]);
    }
    {
        int i = sch(root, 1, n, 1, L == 1 ? 1 : que(root, 1, L - 1, 1, n, 1) + 1);
        int j = tree.schr(1, L, i, 1, n, a[i] + D);
        if (j) ans += (tree.que(1, L, j, 1, n).ld >= D);
    }
    {
        int i = sch(root, 1, n, 1, que(root, 1, R, 1, n, 1));
        int j = tree.schl(1, i, R, 1, n, a[i] + D);
        if (j) ans += (tree.que(1, j, R, 1, n).rd >= D);
    }
    return ans;
}

/*
in1
7 3
10 20 60 40 50 30 70
1 5 10
2 2 100
0 6 17
out1
3
1
2
*/

• Subtask 1: 0 / 4
• Subtask 2: 0 / 11
• Subtask 3: 0 / 12
• Subtask 4: 0 / 14
• Subtask 5: 17 / 17
• Subtask 6: 0 / 19
• Subtask 7: 0 / 23