Submission #1095684

#	Time	Username	Problem	Language	Result	Execution time	Memory
1095684		ConquerConquerer	Circle selection (APIO18_circle_selection)	C++14	0 / 100	1958 ms	1048576 KiB

circle_selection

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

const int maxN = 3e5 + 5;
struct Circle{
    ll x, y, r, id;
} C[maxN];

int n;

bool compC (Circle& a, Circle& b){
    if(a.r == b.r) return a.id < b.id;
    return a.r > b.r;
}
bool isect(Circle& a, Circle& b){
    ll dx = a.x - b.x;
    ll dy = a.y - b.y;
    ll r = a.r + b.r;
    return dx * dx + dy * dy <= r * r;
}

int ans[maxN];
map<pair<ll, ll>, vector<int>> block;
vector<int> tmp;

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

    int n;
    cin >> n;

    for(int i = 1; i <= n; i++){
        cin >> C[i].x >> C[i].y >> C[i].r;
        C[i].id = i;
    }

    sort(C + 1, C + n + 1, compC);

    for (int i = 1; i <= n; i++){
        C[i].x += 1e9;
        C[i].y += 1e9;
        block[{C[i].x / C[i].r, C[i].y / C[i].r}].push_back(i);
    }

    for (int i = 1; i <= n; i++){
        Circle& curr = C[i];
        if (ans[curr.id]) continue;
        for (ll x = curr.x / curr.r - 2; x <= curr.x / curr.r + 2; x++){
            for (ll y = curr.y / curr.r - 2; y <= curr.y / curr.r + 2; y++){
                if (block.find({x,y}) == block.end()) continue;
                for (ll idx: block[{x,y}]){
                    if (ans[C[idx].id] == 0 && isect(C[idx], curr)) ans[C[idx].id] = curr.id;
                        else if (ans[C[idx].id] == 0) tmp.push_back(idx);
                }
                block[{x, y}] = tmp;
            }
        }
    }

    for (int i = 1; i <= n; i++)
        cout << ans[i] << ' ';
    return 0;
}

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