Submission #243162

#	Time	Username	Problem	Language	Result	Execution time	Memory
243162		VEGAnn	Svjetlost (COI18_svjetlost)	C++14	69 / 100	1483 ms	52436 KiB

Main

#include <bits/stdc++.h>
#define sz(x) ((int)x.size())
#define all(x) x.begin(),x.end()
#define PB push_back
using namespace std;
typedef long double ld;
const int N = 400100;
const ld E = 1e-9;
const ld pi = 3.1415926535897;
vector<ld> vc;
int n, pr[N], nt[N], x[N], y[N], nm[N], q;
ld st[4 * N], psh[4 * N];

ld sqr(ld xx) { return xx * xx;}

ld dist(ld x1, ld y1, ld x2, ld y2){
    return sqrt(sqr(x1 - x2) + sqr(y1 - y2));
}

void add(int i, int j){
    ld nw_x = x[j] - x[i];
    ld nw_y = y[j] - y[i];

    ld ang = atan2(nw_y, nw_x);

    if (ang < 0) ang += pi + pi;

    vc.PB(ang);

    ang += pi;

    if (ang >= pi + pi)
        ang -= pi + pi;

    vc.PB(ang);
}

void push(int v){
    if (psh[v] != 0){
        st[v] += psh[v];

        if (v + v + 1 < 4 * N){
            psh[v + v] += psh[v];
            psh[v + v + 1] += psh[v];
        }

        psh[v] = 0;
    }
}

void update(int v, int tl, int tr, int l, int r, ld val){
    push(v);

    if (l > r) return;

    if (tl == l && tr == r) {
        psh[v] += val;
        push(v);
        return;
    }

    int md = (tl + tr) >> 1;

    update(v + v, tl, md, l, min(r, md), val);
    update(v + v + 1, md + 1, tr, max(md + 1, l), r, val);

    st[v] = max(st[v + v], st[v + v + 1]);
}

void add_seg(int i, int j, ld val){
    ld nw_x = x[j] - x[i];
    ld nw_y = y[j] - y[i];

    ld ang = atan2(nw_y, nw_x);

    if (ang < 0) ang += pi + pi;

    int lf = lower_bound(all(vc), ang - E) - vc.begin();

    ang += pi;

    if (ang >= pi + pi)
        ang -= pi + pi;

    int rt = lower_bound(all(vc), ang - E) - vc.begin() - 1;

    if (vc[rt] + E > ang) {
        rt--;
        if (rt < 0)
            rt = sz(vc) - 1;
    }

    if (rt < 0) rt = sz(vc) - 1;

//    cerr << lf << " " << rt << '\n';

    if (lf <= rt){
        update(1, 0, sz(vc) - 1, lf, rt, val);
    } else {
        update(1, 0, sz(vc) - 1, lf, sz(vc) - 1, val);
        update(1, 0, sz(vc) - 1, 0, rt, val);
    }
}

int main(){
    ios_base::sync_with_stdio(0); cin.tie(0);

#ifdef _LOCAL
    freopen("in.txt","r",stdin);
#endif // _LOCAL

    cin >> n;

    for (int i = 0; i < n; i++) {
        cin >> x[i] >> y[i];
        pr[i] = (i - 1 + n) % n;
        nt[i] = (i + 1) % n;
    }

    for (int i = 0; i < n; i++)
        add(i, nt[i]);

    cin >> q;

    for (int i = 0; i < q; i++){
        cin >> nm[i]; nm[i]--;

        int id = nm[i];

        pr[nt[id]] = pr[id];
        nt[pr[id]] = nt[id];

        add(pr[id], nt[id]);
    }

    vc.PB(0);
    vc.PB(pi + pi);

    sort(all(vc));

//    int cnt = 1;
//
//    for (int i = 1; i < sz(vc); i++)
//        if (abs(vc[i] - vc[i - 1]) > E)
//            vc[cnt++] = vc[i];
//
//    vc.resize(cnt);

    for (int i = 0; i < n; i++){
        pr[i] = (i - 1 + n) % n;
        nt[i] = (i + 1) % n;
        add_seg(i, nt[i], dist(x[i], y[i], x[nt[i]], y[nt[i]]));
    }
    cout << fixed << setprecision(10) << st[1] << '\n';

    for (int i = 0; i < q; i++){
        int id = nm[i];

        add_seg(pr[id], id, -dist(x[pr[id]], y[pr[id]], x[id], y[id]));
        add_seg(id, nt[id], -dist(x[id], y[id], x[nt[id]], y[nt[id]]));

        pr[nt[id]] = pr[id];
        nt[pr[id]] = nt[id];

        add_seg(pr[id], nt[id], dist(x[pr[id]], y[pr[id]], x[nt[id]], y[nt[id]]));

        cout << fixed << setprecision(10) << st[1] << '\n';
    }

    return 0;
}

• Subtask 1: 12 / 12
• Subtask 2: 14 / 14
• Subtask 3: 14 / 14
• Subtask 4: 29 / 29
• Subtask 5: 0 / 31