Submission #1211855

#TimeUsernameProblemLanguageResultExecution timeMemory
1211855madamadam3Park (BOI16_park)C++20
0 / 100
323 ms66340 KiB
#include <bits/stdc++.h>

using namespace std;

typedef long long ll;
typedef long double ld;
#define int long long int

struct Circle {
    int x, y; // centre-point
    int rsq, ir; // radius squared, integer radius
};

struct Edge {
    int u, v; ld w;
};

struct DSU {
    int n; vector<int> par, siz;

    DSU(int N) {
        n = N;
        par.resize(n); iota(par.begin(), par.end(), 0);
        siz.assign(n, 1);
    }

    int find(int v) {
        if (par[v] == v) return v;
        return par[v] = find(par[v]);
    }

    void unite(int a, int b) {
        a = find(a); b = find(b);
        if (a != b) {
            if (siz[b] > siz[a]) swap(a, b);
            par[b] = a;
            siz[a] += siz[b];
        }
    }
};

signed main() {
    cin.tie(0)->sync_with_stdio(0);

    // read n, m, w, h and the trees ...
    int n, m; cin >> n >> m;    
    int w, h; cin >> w >> h;

    vector<Circle> trees;
    for (int i = 0; i < n; i++) {
        int x, y, r; cin >> x >> y >> r;
        trees.push_back(Circle {x, y, r*r, r});
    }

    // preprocess ...
    // node n is top wall, n+1 is bottom wall, n+2 is left wall, n+3 is right wall
    vector<Edge> edges;
    for (int i = 0; i < n; i++) {
        edges.push_back(Edge {i, n, ld(h - (trees[i].y + trees[i].ir))});
        edges.push_back(Edge {i, n+1, ld(trees[i].y - trees[i].ir)});
        edges.push_back(Edge {i, n+2, ld(trees[i].x - trees[i].ir)});
        edges.push_back(Edge {i, n+3, ld(w - (trees[i].x + trees[i].ir))});

        for (int j = i + 1; j < n; j++) {
            int dx = trees[i].x - trees[j].x, dy = trees[i].y - trees[j].y;
            edges.push_back(Edge{i, j, sqrt(ld(dx*dx+dy*dy)) - ld(trees[i].ir) - ld(trees[j].ir)});
        }
    }

    sort(edges.begin(), edges.end(), [](Edge &a, Edge &b) {
        return a.w < b.w;
    });

    vector<string> answers(m);
    vector<int> remap(m);
    vector<pair<int, int>> queries(m); // r, e
    for (int i = 0; i < m; i++) {
        cin >> queries[i].first >> queries[i].second;
    }

    iota(remap.begin(), remap.end(), 0);
    sort(remap.begin(), remap.end(), [&](int a, int b) {
        return queries[a].first < queries[b].first;
    });

    auto dsu = DSU(n+4);

    int cq = 0;
    for (auto &el : edges) {
        while (cq < m && el.w > 2 * queries[remap[cq]].first) {
            string ans = "";

            int t = dsu.find(n), b = dsu.find(n+1), l = dsu.find(n+2), r = dsu.find(n+3);
            bool closed[4] = {b == l, b == r, t == r, t == l};

            for (int i = 0; i < 4; i++) {
                if (i == queries[remap[cq]].second - 1) {
                    ans = ans + to_string(i+1);
                    continue;
                }

                if (!closed[queries[remap[cq]].second - 1] && !closed[i]) {
                    ans = ans + to_string(i+1);
                }
            }

            answers[remap[cq]] = ans;
            cq++;
        }

        dsu.unite(el.u, el.v);
    }

    while (cq < m) {
        string ans = "";

        int t = dsu.find(n), b = dsu.find(n+1), l = dsu.find(n+2), r = dsu.find(n+3);
        bool closed[4] = {b == l, b == r, t == r, t == l};

        for (int i = 0; i < 4; i++) {
            if (i == queries[remap[cq]].second - 1) {
                ans = ans + to_string(i+1);
                continue;
            }

            if (!closed[queries[remap[cq]].second - 1] && !closed[i]) {
                ans = ans + to_string(i+1);
            }
        }

        answers[remap[cq]] = ans;
        cq++;
    }

    // answer queries ...
    for (int i = 0; i < m; i++) {
        cout << answers[i] << "\n";
    }
    return 0;
}
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