Submission #1222892

#	Time	Username	Problem	Language	Result	Execution time	Memory
1222892		minhpk	Two Antennas (JOI19_antennas)	C++20	0 / 100	528 ms	30524 KiB

antennas

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

#define mid ((l+r) >> 1)

const int MAXN = 200005;
const int MAXST_SIZE = MAXN * 4;
const long long INF_VAL = (long long)1e16;

struct Element { int h, l, r; };
Element elements[MAXN];
int c,a;
vector<int> in[MAXN], out[MAXN];

struct Query { int l, r, id; };
Query queries[MAXN];

int ans[MAXN];

bool cmp(Query A, Query B) {
    return A.r < B.r;
}

long long t[MAXST_SIZE], t2[MAXST_SIZE], lz[MAXST_SIZE];

void lazy_update(int node_id, int l, int r) {
    if (lz[node_id] != -INF_VAL) {
        t2[node_id] = max(t2[node_id], lz[node_id] - t[node_id]);
        if (l != r) {
            lz[node_id * 2] = max(lz[node_id * 2], lz[node_id]);
            lz[node_id * 2 + 1] = max(lz[node_id * 2 + 1], lz[node_id]);
        }
        lz[node_id] = -INF_VAL;
    }
}

void build(int node_id, int l, int r) {
    lz[node_id] = -INF_VAL;
    t[node_id] = INF_VAL + 10;
    t2[node_id] = -INF_VAL;
    if (l == r) return;
    build(node_id * 2, l, mid);
    build(node_id * 2 + 1, mid + 1, r);
}

void update_point(int node_id, int l, int r, int pos, int val) {
    lazy_update(node_id, l, r);
    if (l == r) {
        t[node_id] = val;
        return;
    }
    if (pos <= mid) {
        update_point(node_id * 2, l, mid, pos, val);
    } else {
        update_point(node_id * 2 + 1, mid + 1, r, pos, val);
    }
    t[node_id]  = min(t[node_id * 2], t[node_id * 2 + 1]);
    t2[node_id] = max(t2[node_id * 2], t2[node_id * 2 + 1]);
}

void update_range(int node_id, int l, int r, int query_l, int query_r, int val) {
    lazy_update(node_id, l, r);
    if (query_r < l || r < query_l) return;
    if (query_l <= l && r <= query_r) {
        lz[node_id] = max(lz[node_id], val);
        lazy_update(node_id, l, r);
        return;
    }
    update_range(node_id * 2, l, mid, query_l, query_r, val);
    update_range(node_id * 2 + 1, mid + 1, r, query_l, query_r, val);
    t[node_id]  = min(t[node_id * 2], t[node_id * 2 + 1]);
    t2[node_id] = max(t2[node_id * 2], t2[node_id * 2 + 1]);
}

int find_max_diff(int node_id, int l, int r, int query_l, int query_r) {
    lazy_update(node_id, l, r);
    if (query_r < l || r < query_l) return -INF_VAL;
    if (query_l <= l && r <= query_r) return t2[node_id];
    return max(
        find_max_diff(node_id * 2, l, mid, query_l, query_r),
        find_max_diff(node_id * 2 + 1, mid + 1, r, query_l, query_r)
    );
}

void solve_queries(int num_elements) {
    build(1, 1, num_elements);
    int current_right_endpoint = 0;

    for (int i = 1; i <= c; i++) {
        int L = queries[i].l, R = queries[i].r, query_id = queries[i].id;

        while (current_right_endpoint < R) {
            current_right_endpoint++;
            for (int p : in[current_right_endpoint]) {
                update_point(1, 1, num_elements, p, elements[p].h);
            }
            for (int p : out[current_right_endpoint]) {
                update_point(1, 1, num_elements, p, INF_VAL + 10);
            }

            int lower_bound_j = max(1LL, current_right_endpoint - elements[current_right_endpoint].r);
            int upper_bound_j = max(1LL, current_right_endpoint - elements[current_right_endpoint].l);

            if (lower_bound_j <= upper_bound_j) {
                update_range(1, 1, num_elements, lower_bound_j, upper_bound_j, elements[current_right_endpoint].h);
            }
        }
        ans[query_id] = max(ans[query_id], find_max_diff(1, 1, num_elements, L, R));
    }
}

signed main() {
    ios::sync_with_stdio(false);
    cin.tie(NULL);

    cin >> a;
    for (int i = 1; i <= a; i++) {
        cin >> elements[i].h >> elements[i].l >> elements[i].r;
        if (i + elements[i].l <= a) in[i + elements[i].l].push_back(i);
        if (i + elements[i].r <= a) out[i + elements[i].r + 1].push_back(i);
    }

    cin >> c;
    for (int i = 1; i <= c; i++) {
        cin >> queries[i].l >> queries[i].r;
        queries[i].id = i;
    }

    sort(queries + 1, queries + 1 + c, cmp);
    for (int i = 1; i <= c; i++) ans[i] = -1;

    solve_queries(a);

    for (int i = 1; i <= a; i++) {
        elements[i].h = INF_VAL - elements[i].h + 1;
        in[i].clear();
        out[i].clear();
    }
    for (int i = a + 1; i < MAXN; ++i) {
        in[i].clear();
        out[i].clear();
    }

    for (int i = 1; i <= a; i++) {
        if (i + elements[i].l <= a) in[i + elements[i].l].push_back(i);
        if (i + elements[i].r <= a) out[i + elements[i].r + 1].push_back(i);
    }

    solve_queries(a);

    for (int i = 1; i <= c; i++) {
        cout << ans[i] << "\n";
    }
    return 0;
}

• Subtask 1: 0 / 2
• Subtask 2: 0 / 11
• Subtask 3: 0 / 22
• Subtask 4: 0 / 65