Submission #499271

#	Time	Username	Problem	Language	Result	Execution time	Memory
499271		_martynas	Circle selection (APIO18_circle_selection)	C++14	87 / 100	3080 ms	656396 KiB

circle_selection

#include <bits/stdc++.h>

using namespace std;
using namespace std::chrono;

using ll = long long;

const ll MOD = 1e9+7;

const int MAX_N = 3e5+5;

int n;
ll X[MAX_N], Y[MAX_N], R[MAX_N];
int P[MAX_N];
bool visited[MAX_N];
int Inh[MAX_N];

struct LLNode
{
    int idx;
    LLNode* next = nullptr;

    LLNode()
    {
    }

    LLNode(int val)
        : idx(val)
    {
    }
} LLNodes[MAX_N];
int llcounter = 0;

inline LLNode* getLLNode()
{
    return &LLNodes[llcounter++];
}

int dup;

struct Quad
{
    ll l, r, bot, top;
    array<Quad*, 4> childs = {};
    LLNode* llnode = nullptr;
    int sz;

    Quad()
    {
    }

    Quad(ll _l, ll _r, ll _bot, ll _top)
        : l(_l), r(_r), bot(_bot), top(_top)
    {
        sz = 0;
    }

    void add(ll x, ll y, int idx)
    {
        if(x < l || x > r || y < bot || y > top) {
            return;
        }

        sz++;
//        cerr << "l = " << l << ", r = " << r << ", "
//             << "bot = " << bot << ", top = " << top << "\n";
        if(l == r && bot == top) {
            if(llnode == nullptr) {
                llnode = getLLNode();
                llnode->idx = idx;
            }
            else {
                dup++;
                LLNode* temp = getLLNode();
                temp->idx = idx;
                temp->next = llnode;
                llnode = temp;
            }
        }
        else {
            ll midH, midV;
            midH = l+(r-l)/2;
            midV = bot+(top-bot)/2;

            if(l != r && top != bot) {
                if(childs[0] == nullptr && !(x < l || x > midH || y < bot || y > midV)) {
                    childs[0] = new Quad(l, midH, bot, midV);
                }
                else if(childs[1] == nullptr && !(x < midH+1 || x > r || y < bot || y > midV)) {
                    childs[1] = new Quad(midH+1, r, bot, midV);
                }
                else if(childs[2] == nullptr && !(x < l || x > midH || y < midV+1 || y > top)) {
                    childs[2] = new Quad(l, midH, midV+1, top);
                }
                else if(childs[3] == nullptr && !(x < midH+1 || x > r || y < midV+1 || y > top)) {
                    childs[3] = new Quad(midH+1, r, midV+1, top);
                }
            }
            else if(l != r) {
                if(childs[0] == nullptr && !(x < l || x > midH || y < bot || y > top)) {
                    childs[0] = new Quad(l, midH, bot, midV);
                }
                else if(childs[1] == nullptr && !(x < midH+1 || x > r || y < bot || y > top)) {
                    childs[1] = new Quad(midH+1, r, bot, top);
                }
            }
            else if(top != bot) {
                if(childs[0] == nullptr && !(x < l || x > r || y < bot || y > midV)) {
                    childs[0] = new Quad(l, r, bot, midV);
                }
                else if(childs[1] == nullptr && !(x < l || x > r || y < midV+1 || y > top)) {
                    childs[1] = new Quad(l, r, midV+1, top);
                }
            }

            for(int k = 0; k < 4; k++) {
                if(childs[k] != nullptr) {
                    childs[k]->add(x, y, idx);
                }
            }
        }
    }

    void setInRange(ll x, ll y, ll radius, int idx)
    {
        if(x+2*radius < l || x-2*radius > r || y+2*radius < bot || y-2*radius > top || sz == 0) {
            return;
        }
//        cerr << "l = " << l << ", r = " << r << ", "
//             << "bot = " << bot << ", top = " << top << "\n";
        if(l == r && bot == top) {
            while(llnode != nullptr &&
                (R[idx]+R[llnode->idx])*(R[idx]+R[llnode->idx])
                >= llabs(X[idx]-X[llnode->idx])*llabs(X[idx]-X[llnode->idx])
                +llabs(Y[idx]-Y[llnode->idx])*llabs(Y[idx]-Y[llnode->idx])) {
                P[llnode->idx] = idx;
                visited[llnode->idx] = true;
                sz--;
                llnode = llnode->next;
            }
            return;
        }

        int cnt = 0;
        for(int k = 0; k < 4; k++) {
            if(childs[k] != nullptr) {
                childs[k]->setInRange(x, y, radius, idx);
                cnt += childs[k]->sz;
            }
        }
        sz = cnt;
    }
};

Quad Q(-1000000000, 1000000000, -1000000000, 1000000000);

int main()
{
    auto stop = steady_clock::now();

    cin >> n;
    for(int i = 0; i < n; i++) {
        cin >> X[i] >> Y[i] >> R[i];
    }
    iota(P, P+n, 0);

//    cerr << "Exec: " << duration_cast<milliseconds>(steady_clock::now()-stop).count() << " ms\n";

    vector<int> I(n);
    iota(I.begin(), I.end(), 0);
    sort(I.begin(), I.end(),
    [&](int a, int b)
    {
        return R[a] > R[b] || (R[a] == R[b] && a < b);
    });

    for(int i = n-1; i >= 0; i--) {
        int idx = I[i];
        //cerr << i << " started\n";
        Q.add(X[idx], Y[idx], idx);
        //cerr << i << " finished\n";
    }

    for(int i = 0; i < n; i++) {
        int idx = I[i];
        if(visited[idx]) continue;
        Q.setInRange(X[idx], Y[idx], R[idx], idx);
    }

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

//    cerr << "Dupe: " << dup << "\n";
//    cerr << "Exec: " << duration_cast<milliseconds>(steady_clock::now()-stop).count() << " ms\n";

    return 0;
}
/*
11
9 9 2
13 2 1
11 8 2
3 3 2
3 12 1
12 14 1
9 8 5
2 8 2
5 2 1
14 4 2
14 14 1
*/

Compilation message (stderr)

circle_selection.cpp: In function 'int main()':
circle_selection.cpp:159:10: warning: variable 'stop' set but not used [-Wunused-but-set-variable]
  159 |     auto stop = steady_clock::now();
      |          ^~~~

• Subtask 1: 7 / 7
• Subtask 2: 12 / 12
• Subtask 3: 15 / 15
• Subtask 4: 23 / 23
• Subtask 5: 30 / 30
• Subtask 6: 0 / 13