Submission #586665

#	Time	Username	Problem	Language	Result	Execution time	Memory
586665		Jomnoi	Park (BOI16_park)	C++17	100 / 100	323 ms	56160 KiB

park

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

const int MAX_N = 2005;

long long X[MAX_N], Y[MAX_N], R[MAX_N];
long long dist[MAX_N][MAX_N];
long long wall[5][5];
int parent[MAX_N];

int find_parent(int u) {
    if(u == parent[u]) {
        return u;
    }
    return parent[u] = find_parent(parent[u]);
}

void merge(int u, int v) {
    u = find_parent(u), v = find_parent(v);
    if(u == v) {
        return;

    }

    parent[v] = u;
}

int main() {
    cin.tie(nullptr)->sync_with_stdio(false);

    int N, M, W, H;
    cin >> N >> M >> W >> H;

    for(int i = 0; i < N; i++) {
        cin >> X[i] >> Y[i] >> R[i];
    }

    vector <tuple <long long, int, int>> edges;
    for(int i = 0; i < N; i++) {
        for(int j = i + 1; j < N; j++) {
            dist[i][j] = sqrt((X[i] - X[j]) * (X[i] - X[j]) + (Y[i] - Y[j]) * (Y[i] - Y[j])) - R[i] - R[j];
        }
    }    

    for(int i = 0; i < N; i++) {
        dist[i][N + 3] = H - Y[i] - R[i];
        dist[i][N + 2] = W - X[i] - R[i];
        dist[i][N + 1] = Y[i] - R[i];
        dist[i][N + 0] = X[i] - R[i];
    }

    for(int i = 0; i < N; i++) {
        for(int j = i + 1; j < N + 4; j++) {
            edges.emplace_back(dist[i][j], i, j);
        }
    }

    sort(edges.begin(), edges.end()); 

    for(int i = 0; i < N + 4; i++) {
        parent[i] = i;
    }
    for(int i = 0; i < 4; i++) {
        for(int j = 0; j < 4; j++) {
            wall[i][j] = -1;
        }
    }
    for(auto [d, u, v] : edges) {
        merge(u, v);

        for(int i = 0; i < 4; i++) {
            for(int j = 0; j < 4; j++) {
                if(i == j or wall[i][j] != -1) {
                    continue;
                }

                if(find_parent(N + i) == find_parent(N + j)) {
                    wall[i][j] = d;
                }
            }
        }
    }

    while(M--) {
        int r, e;
        cin >> r >> e;

        e--;
        for(int i = 0; i < 4; i++) {
            bool ok = true;
            if(i != e) {
                ok &= (wall[(i + 1) % 4][i] >= 2 * r);
                ok &= (wall[(e + 1) % 4][e] >= 2 * r);
                if((4 + i - e) % 4 >= 2) {
                    ok &= (wall[e][(e + 2) % 4] >= 2 * r);
                }
                if((4 + i - e) % 4 <= 2) {
                    ok &= (wall[(e + 1) % 4][(e + 3) % 4] >= 2 * r);
                }
            }

            if(ok == true) {
                cout << i + 1;
            }
        }
        cout << '\n';
    }
    return 0;
}

• Subtask 1: 27 / 27
• Subtask 2: 31 / 31
• Subtask 3: 42 / 42