Submission #578347

#	Time	Username	Problem	Language	Result	Execution time	Memory
578347		Johann	Two Antennas (JOI19_antennas)	C++14	0 / 100	65 ms	29548 KiB

antennas

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

#define pii pair<int,int>
#define tiii tuple<int,int,int>
#define vi vector<int>
#define vpii vector<pii>
#define vtiii vector<tiii>
#define sz(x) (int) (x).size()
#define all(x) (x).begin(), (x).end()

struct item {
    int mini = INT_MAX;
    int maxi = INT_MIN;
    int res = -1;
    int op = -1;
    bool active = false;
};

struct SegTree {
    vector<item> arr;
    int size;
    item cmp(item & a, item & b, item & res) {
        res.mini = min(
                (a.active) ? a.mini : INT_MAX, (b.active) ? b.mini : INT_MAX );
        res.maxi = max(
                (a.active) ? a.maxi : INT_MIN, (b.active) ? b.maxi : INT_MIN );
        res.res = max(res.res, max(a.res, b.res));
        res.active = a.active | b.active;
    }
    void apply(int x) {
        if (arr[x].op == -1) return;
        int nres =  INT_MIN;
        if (arr[x].active) nres = max(abs(arr[x].mini - arr[x].op), abs(arr[x].maxi - arr[x].op) );
        arr[x].res = max(arr[x].res, nres);
        if (2 * x < sz(arr) && nres > arr[2 * x].res) { apply(2 * x); arr[2 * x].op = arr[x].op; }
        if (2*x+1 < sz(arr) && nres > arr[2*x+1].res) { apply(2*x+1); arr[2*x+1].op = arr[x].op; }
        arr[x].op = -1;
    }
    void init(vi & H) {
        size = 1;
        while (size < sz(H)) size *= 2;
        arr.assign(2 * size, item());
        for (int i = 0; i < sz(H); ++i) {
            arr[size + i].mini = H[i];
            arr[size + i].maxi = H[i];
        }
        for (int i = size-1; i > 0; --i) {
            cmp(arr[2 * i], arr[2 * i + 1], arr[i]);
        }
    }
    void setState(int i, bool state, int x, int lx, int rx ) {
        apply(x);
        if (rx - lx == 1) { arr[x].active = state; return; }
        int m = (lx + rx) / 2;
        if (i < m) setState(i, state, 2 * x, lx, m);
        else setState(i, state, 2 * x + 1, m, rx);
        apply(2*x), apply(2*x+1);
        cmp(arr[2*x], arr[2*x+1], arr[x]);
    }
    void setState(int i, bool state) {
        setState(i, state, 1, 0, size);
    }
    void update(int l, int r, int h, int x, int lx, int rx ) {
        apply(x);
        if (rx <= l || r <= lx) return;
        if (l <= lx && rx <= r) { // in
            arr[x].op = h;
            return;
        }
        int m = (lx + rx) / 2;
        update(l, r, h, 2 * x, lx, m);
        update(l, r, h, 2 * x + 1, m, rx);
        apply(2*x); apply(2*x+1);
        cmp(arr[2*x], arr[2*x+1], arr[x]);
    }
    void update(int l, int r, int h) {
        update(l, r, h, 1, 0, size);
    }
    int query(int l, int r, int x, int lx, int rx ) {
        apply(x);
        if (rx <= l || r <= lx) return -1;
        if (l <= lx && rx <= r) return arr[x].res;
        int m = (lx + rx) / 2;
        int a = query(l, r, 2 * x, lx, m);
        int b = query(l, r, 2 * x + 1, m, rx);
        return max(a,b);
    }
    int query(int l, int r) {
        return query(l, r, 1, 0, size);
    }
};

int main() {
    ios::sync_with_stdio(false);
    cin.tie(0);
    cout.tie(0);

    int n;
    cin >> n;
    vi H(n), A(n), B(n);
    for (int i = 0; i < n; ++i) { cin >> H[i] >> A[i] >> B[i]; }
    int q;
    cin >> q;
    vtiii Q(q);
    for (int i = 0,l,r; i < q; ++i) {
        cin >> l >> r; --l; --r;
        Q[i] = { l, r, i };
    }
    vi ans(q, -1);

    priority_queue<pii, vpii, greater<pii>> activate;
    priority_queue<pii, vpii, greater<pii>> deactivate;

    SegTree seg;
    seg.init(H);
    sort(all(Q), [&](tiii & a, tiii & b){
        return get<1>(a) > get<1>(b);
    }); // Niedrige Endpunkte nach hinten, dann kann man den Vektor als queue verwenden

    for (int i = 0; i < n; ++i) {
        activate.push({i + A[i], i});
        deactivate.push({i + B[i], i});
        while (!activate.empty() && activate.top().first == i) {
            seg.setState(activate.top().second, true);
            activate.pop();
        }

        int l = i - B[i];
        int r = i - A[i] + 1;
        seg.update(l, r, H[i]);

        while (!Q.empty() && get<1>(Q.back()) == i) {
            int idx;
            tie(l,r,idx) = Q.back(); Q.pop_back();
            ans[idx] = seg.query(l,r);
        }

        while(!deactivate.empty() && deactivate.top().first == i) {
            seg.setState(deactivate.top().second, false);
            deactivate.pop();
        }
    }

    for (int x : ans) cout << x << "\n";

}

Compilation message (stderr)

antennas.cpp: In member function 'item SegTree::cmp(item&, item&, item&)':
antennas.cpp:30:5: warning: no return statement in function returning non-void [-Wreturn-type]
   30 |     }
      |     ^

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