Submission #366884

#	Time	Username	Problem	Language	Result	Execution time	Memory
366884		valerikk	Two Antennas (JOI19_antennas)	C++17	100 / 100	1032 ms	45540 KiB

antennas

#include <bits/stdc++.h>
using namespace std;
  
const int N = 3e5 + 7;
const int INF = 1e9 + 1010;
  
int n, q;
int h[N], a[N], b[N];
int L[N], R[N];
int ans[N];
int c[N];
int t[4 * N]; // max d[i]
int min_h[4 * N]; 
int max_c[4 * N];
vector<pair<int, int>> events[N];
vector<int> here[N];
  
void upd(int i, int val) {
    /*if (i == 9 && val == 3) {
        cout << max_c[i] << endl;
    }*/
    min_h[i] = min(min_h[i], val);
    t[i] = max(t[i], max_c[i] - min_h[i]);
    /*if (i == 9 && val == 3) {
        cout << t[i] << " " << max_c[i] << " " << min_h[i] << endl;
    }*/
}
  
void push(int i) {
    upd(2 * i, min_h[i]);
    upd(2 * i + 1, min_h[i]);
    min_h[i] = INF;
}
  
void pull(int i) {
    max_c[i] = max(max_c[2 * i], max_c[2 * i + 1]);
    t[i] = max({t[i], max_c[i] - min_h[i], t[2 * i], t[2 * i + 1]});
} 
 
void upd_seg(int i, int l, int r, int ql, int qr, int val) {
    if (l >= qr || r <= ql)
        return;
    if (l >= ql && r <= qr) {
        /*if (val == 3) {
            cout << i << " " << l << " " << r << endl;
        }*/
        upd(i, val);
        /*if (val == 3) {
            cout << t[i] << endl;
        }*/
        return;
    }
  
    push(i);
    int m = (l + r) / 2;
    upd_seg(2 * i, l, m, ql, qr, val);
    upd_seg(2 * i + 1, m, r, ql, qr, val);
    pull(i);
}
  
void upd_c(int i, int l, int r, int pos, int new_c) {
    if (r - l == 1) {
        min_h[i] = INF;
        c[pos] = max_c[i] = new_c;
    } else {
        push(i);
        int m = (l + r) / 2;
        if (pos < m)
            upd_c(2 * i, l, m, pos, new_c);
        else
            upd_c(2 * i + 1, m, r, pos, new_c);
        pull(i);
    }
}
  
int get_max(int i, int l, int r, int ql, int qr) {
    if (l >= qr || r <= ql)
        return -1;
    if (l >= ql && r <= qr) {
        //cout << i << " " << l << " " << r << " " << t[i] << endl;
        return t[i];
    }
    push(i);
    int m = (l + r) / 2;
    return max(get_max(2 * i, l, m, ql, qr), get_max(2 * i + 1, m, r, ql, qr));
}
  
void build(int i, int l, int r) {
    min_h[i] = INF;
    max_c[i] = -1;
    t[i] = -1;
    if (r - l == 1) {
        c[l] = -1;
    } else {
        int m = (l + r) / 2;
        build(2 * i, l, m);
        build(2 * i + 1, m, r);
    }
}
  
void solve() {
    for (int i = 0; i <= n; i++) {
        events[i].clear();
        here[i].clear();
    }
    for (int i = 0; i < n; i++) {
        int l = i + a[i], r = min(n, i + b[i] + 1);
        if (l < r) {
            events[l].emplace_back(i, h[i]);
            events[r].emplace_back(i, -INF);
        }
    }
      
    for (int i = 0; i < q; i++) 
        here[R[i]].push_back(i);
      
    build(1, 0, n);
    for (int i = 0; i <= n; i++) {
        for (int qid : here[i]) 
            ans[qid] = max(ans[qid], get_max(1, 0, n, L[qid], R[qid]));
  
        for (auto [pos, new_c] : events[i]) {
            //cout << "upd_c " << pos << " " << new_c << endl;
            upd_c(1, 0, n, pos, new_c);
        }
        if (i != n) {
            int l = max(0, i - b[i]), r = i - a[i] + 1;
            //cout << "segadd " << i << " " << l << " " << r << " " << h[i] << endl;
            /*if (h[i] == 3) 
                cout << l << " " << r << endl;*/
            if (l < r)
                upd_seg(1, 0, n, l, r, h[i]);
        }
    }
}
  
int main() {
#ifdef LOCAL
    freopen("input.txt", "r", stdin);
#endif
    ios::sync_with_stdio(false);
    cin.tie(0);
    cin >> n;
    for (int i = 0; i < n; i++) 
        cin >> h[i] >> a[i] >> b[i];
    cin >> q;
    for (int i = 0; i < q; i++) {
        cin >> L[i] >> R[i];
        L[i]--;
        ans[i] = -1;
    }
      
    for (int _ = 0; _ < 2; _++) {
        solve();
        reverse(h, h + n);
        reverse(a, a + n);
        reverse(b, b + n);
        for (int i = 0; i < q; i++) {
            R[i]--;
            L[i] = n - 1 - L[i];
            R[i] = n - 1 - R[i];
            swap(L[i], R[i]);
            R[i]++;
        }
    }
     
    for (int i = 0; i < q; i++) 
        cout << ans[i] << "\n";
    return 0;
}

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