Submission #921310

#	Time	Username	Problem	Language	Result	Execution time	Memory
921310		boris_mihov	Two Antennas (JOI19_antennas)	C++17	100 / 100	489 ms	363132 KiB

antennas

#include <algorithm>
#include <iostream>
#include <numeric>
#include <cassert>
#include <vector>

typedef long long llong;
const int MAXN = 2000000 + 10;
const int INF = 1e9;

int n, q;
struct SegmentTree
{
    struct Node
    {
        int height;
        int answer;
        int lazyMAX;
        int lazyMIN;
        int minActiveHeight;
        int maxActiveHeight;

        Node()
        {
            lazyMAX = -INF;
            lazyMIN = INF;
            minActiveHeight = INF;
            maxActiveHeight = -INF;
            answer = -1;
            height = 0;
        }

        friend Node operator + (const Node &left, const Node &right)
        {
            Node res;
            res.answer = std::max(left.answer, right.answer);
            res.minActiveHeight = std::min(left.minActiveHeight, right.minActiveHeight);
            res.maxActiveHeight = std::max(left.maxActiveHeight, right.maxActiveHeight);
            return res;
        }
    };

    Node tree[4*MAXN];
    void push(int node, int l, int r)
    {
        if (tree[node].lazyMAX == -INF && tree[node].lazyMIN == INF)
        {
            return;
        }

        tree[node].answer = std::max(tree[node].answer, tree[node].lazyMAX - tree[node].minActiveHeight);
        tree[node].answer = std::max(tree[node].answer, tree[node].maxActiveHeight - tree[node].lazyMIN);

        if (l < r)
        {
            tree[2*node].lazyMAX = std::max(tree[2*node].lazyMAX, tree[node].lazyMAX);
            tree[2*node].lazyMIN = std::min(tree[2*node].lazyMIN, tree[node].lazyMIN);
            tree[2*node + 1].lazyMAX = std::max(tree[2*node + 1].lazyMAX, tree[node].lazyMAX);
            tree[2*node + 1].lazyMIN = std::min(tree[2*node + 1].lazyMIN, tree[node].lazyMIN);
        }

        tree[node].lazyMAX = -INF;
        tree[node].lazyMIN = INF;
    }

    void updateHeight(int l, int r, int node, int queryPos, int queryVal)
    {
        push(node, l, r);
        if (queryPos < l || r < queryPos)
        {
            return;
        }

        if (l == r)
        {
            tree[node].height = queryVal;
            tree[node].minActiveHeight = (queryVal == 0 ? INF : queryVal);
            tree[node].maxActiveHeight = (queryVal == 0 ? -INF : queryVal);
            return;
        }

        int mid = (l + r) / 2;
        updateHeight(l, mid, 2*node, queryPos, queryVal);
        updateHeight(mid + 1, r, 2*node + 1, queryPos, queryVal);
        tree[node] = tree[2*node] + tree[2*node + 1];
    }

    void updateRange(int l, int r, int node, int queryL, int queryR, int queryVal)
    {
        push(node, l, r);
        if (queryR < l || r < queryL)
        {
            return;
        }

        if (queryL <= l && r <= queryR)
        {
            tree[node].lazyMAX = queryVal;
            tree[node].lazyMIN = queryVal;
            push(node, l, r);
            return;
        }

        int mid = (l + r) / 2;
        updateRange(l, mid, 2*node, queryL, queryR, queryVal);
        updateRange(mid + 1, r, 2*node + 1, queryL, queryR, queryVal);
        tree[node] = tree[2*node] + tree[2*node + 1];
    }

    int query(int l, int r, int node, int queryL, int queryR)
    {
        push(node, l, r);
        if (queryL <= l && r <= queryR)
        {
            return tree[node].answer;
        }

        int res = -1;
        int mid = (l + r) / 2;
        if (queryL <= mid) res = std::max(res, query(l, mid, 2*node, queryL, queryR));
        if (mid + 1 <= queryR) res = std::max(res, query(mid + 1, r, 2*node + 1, queryL, queryR));
        return res;
    }

    void updateHeight(int pos, int val)
    {
        updateHeight(1, n, 1, pos, val);
    }

    void updateRange(int l, int r, int val)
    {
        updateRange(1, n, 1, l, r, val);
    }

    int query(int l, int r)
    {
        return query(1, n, 1, l, r);
    }
};

int a[MAXN];
int b[MAXN];
int h[MAXN];
int answer[MAXN];
std::vector <int> add[MAXN];
std::vector <int> rem[MAXN];
std::vector <std::pair <int,int>> queries[MAXN];
SegmentTree tree;

void solve()
{
    for (int i = 1 ; i <= n ; ++i)
    {
        add[a[i] + i].push_back(i);
        rem[b[i] + i + 1].push_back(i);
    }

    for (int i = 1 ; i <= n ; ++i)
    {
        for (const int &idx : add[i])
        {
            tree.updateHeight(idx, h[idx]);
        }

        for (const int &idx : rem[i])
        {
            tree.updateHeight(idx, 0);
        }

        if (i - a[i] > 0)
        {
            tree.updateRange(std::max(1, i - b[i]), std::max(1, i - a[i]), h[i]);
        }

        for (const auto &[l, idx] : queries[i])
        {
            answer[idx] = tree.query(l, i);
        }
    }
}

void input()
{
    std::cin >> n;
    for (int i = 1 ; i <= n ; ++i)
    {
        std::cin >> h[i] >> a[i] >> b[i];
    }

    std::cin >> q;
    for (int i = 1 ; i <= q ; ++i)
    {
        int l, r;
        std::cin >> l >> r;
        queries[r].push_back({l, i});
    }
}

void print()
{
    for (int i = 1 ; i <= q ; ++i)
    {
        std::cout << answer[i] << '\n';
    }
}

void fastIOI()
{
    std::ios_base :: sync_with_stdio(0);
    std::cout.tie(nullptr);
    std::cin.tie(nullptr);
}

int main()
{
    fastIOI();
    input();
    solve();
    print();

    return 0;
}

• Subtask 1: 2 / 2
• Subtask 2: 11 / 11
• Subtask 3: 22 / 22
• Subtask 4: 65 / 65