oj.uz

Submission #752078

# Submission time Handle Problem Language Result Execution time Memory
752078 2023-06-02T09:12:18 Z PanosPask Park (BOI16_park) C++14
100 / 100
 401 ms 39836 KB 
#include <bits/stdc++.h>
#define mp make_pair
#define f first
#define s second

using namespace std;

const int LEFT = 0, DOWN = 1, RIGHT = 2, UP = 3;
const int BL = 0, BR = 1, TR = 2, TL = 3;

typedef pair<int, int> pi;
typedef long long ll;

struct UnionFind {

    int size;
    vector<int> rep;
    vector<int> rank;

    void init(int n) {
        size = n;
        rank.assign(size, 0);

        rep.resize(size);
        for (int i = 0; i < size; i++)
            rep[i] = i;
    }

    int find(int a) {
        if (a != rep[a])
            rep[a] = find(rep[a]);

        return rep[a];
    }

    bool same(int a, int b) {
        return find(a) == find(b);
    }

    void unite(int a, int b) {
        a = find(a);
        b = find(b);

        if (a == b)
            return;

        if (rank[a] == rank[b])
            rank[a]++;
        if (rank[b] > rank[a])
            swap(a, b);

        rep[b] = a;
    }
};

struct Tree {
    int x, y, radius;
};

struct MaxDiameter {
    int a, b;
    double w;
};

bool operator < (const MaxDiameter& a, const MaxDiameter& b)
{
    return a.w < b.w;
}

int n, m;
int W, H;
UnionFind dsu;
vector<Tree> trees;
vector<pair<pi, int>> visitors;
vector<set<int>> adj_list;
vector<vector<int>> ans;
vector<int> vis;
vector<MaxDiameter> edges;
int cur;

void CreateEdgeTrees(Tree& a, Tree& b, int a_id, int b_id)
{
    double dist = sqrt((ll)(a.x - b.x) * (a.x - b.x) + (ll)(a.y - b.y) * (a.y - b.y));

    MaxDiameter c;
    c.w = dist - a.radius - b.radius;
    c.a = a_id;
    c.b = b_id;

    edges.push_back(c);
}

void CreateEdgeBorder(Tree& a, int b, int a_id)
{
    MaxDiameter c;
    c.a = a_id;
    c.b = b;
    c.w = 0 - a.radius;

    if (b == LEFT) {
        c.w += a.x;
    }
    else if (b == DOWN) {
        c.w += a.y;
    }
    else if (b == RIGHT) {
        c.w += W - a.x;
    }
    else
        c.w += H - a.y;

    edges.push_back(c);
}

void remove_from_all(int i)
{
    for (int k = 0; k < 4; k++)
        adj_list[k].erase(i);
}

void dfs(int node)
{
    if (vis[node])
        return;

    ans[cur].push_back(node);
    vis[node] = true;

    for (auto& neigh : adj_list[node])
        dfs(neigh);
}

int main(void)
{
    scanf("%d %d", &n, &m);
    scanf("%d %d", &W, &H);

    trees.resize(n);
    for (int i = 0; i < n; i++)
        scanf("%d %d %d", &trees[i].x, &trees[i].y, &trees[i].radius);

    visitors.resize(m);
    ans.resize(m);
    for (int j = 0; j < m; j++) {
        scanf("%d %d", &visitors[j].f.f, &visitors[j].f.s);
        visitors[j].s = j;
    }
    sort(visitors.begin(), visitors.end());

    for (int i = 0; i < n; i++) {
        for (int j = i + 1; j < n; j++) {
            CreateEdgeTrees(trees[i], trees[j], i + 4, j + 4);
        }

        CreateEdgeBorder(trees[i], LEFT, i + 4);
        CreateEdgeBorder(trees[i], DOWN, i + 4);
        CreateEdgeBorder(trees[i], RIGHT, i + 4);
        CreateEdgeBorder(trees[i], UP, i + 4);
    }
    sort(edges.begin(), edges.end());

    // Initially, all entrances are connected
    adj_list.resize(4);
    for (int i = 0; i < 4; i++)
        for (int j = 0; j < 4; j++)
            if (i != j)
                adj_list[i].insert(j);

    int cur_add = 0;
    dsu.init(n + 4);
    bool bottomtop = true, leftright = true, lefttop = true, leftbottom = true, righttop = true, rightbottom = true;

    for (int v = 0; v < m; v++) {
        int r, e, id;
        id = visitors[v].s;
        r = visitors[v].f.f;
        e = visitors[v].f.s - 1;

        while (cur_add < edges.size() && (edges[cur_add].w < 2 * r || edges[cur_add].w == 0)) {
            dsu.unite(edges[cur_add].a, edges[cur_add].b);
            cur_add++;
        }

        // Check the cases!
        if (bottomtop && dsu.same(LEFT, RIGHT)) {
            bottomtop = false;
            adj_list[TL].erase(BL);
            adj_list[TL].erase(BR);
            adj_list[TR].erase(BL);
            adj_list[TR].erase(BR);

            adj_list[BL].erase(TL);
            adj_list[BL].erase(TR);
            adj_list[BR].erase(TL);
            adj_list[BR].erase(TR);
        }
        if (leftright && dsu.same(DOWN, UP)) {
            leftright = false;
            adj_list[TL].erase(TR);
            adj_list[TL].erase(BR);
            adj_list[BL].erase(TR);
            adj_list[BL].erase(BR);

            adj_list[TR].erase(TL);
            adj_list[TR].erase(BL);
            adj_list[BR].erase(TL);
            adj_list[BR].erase(BL);
        }

        if (lefttop && dsu.same(LEFT, UP)) {
            lefttop = false;
            adj_list[TL].clear();

            remove_from_all(TL);
        }
        if (righttop && dsu.same(RIGHT, UP)) {
            righttop = false;
            adj_list[TR].clear();

            remove_from_all(TR);
        }
        if (rightbottom && dsu.same(RIGHT, DOWN)) {
            rightbottom = false;
            adj_list[BR].clear();

            remove_from_all(BR);
        }
        if (leftbottom && dsu.same(LEFT, DOWN)) {
            leftbottom = false;
            adj_list[BL].clear();

            remove_from_all(BL);
        }

        vis.assign(4, false);
        cur = id;
        dfs(e);
        sort(ans[cur].begin(), ans[cur].end());
    }

    for (int i = 0; i < m; i++) {
        for (int j = 0; j < ans[i].size(); j++)
            printf("%d", ans[i][j] + 1);
        printf("\n");
    }
}

Compilation message

park.cpp: In function 'int main()':
park.cpp:179:24: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<MaxDiameter>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  179 |         while (cur_add < edges.size() && (edges[cur_add].w < 2 * r || edges[cur_add].w == 0)) {
      |                ~~~~~~~~^~~~~~~~~~~~~~
park.cpp:242:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  242 |         for (int j = 0; j < ans[i].size(); j++)
      |                         ~~^~~~~~~~~~~~~~~
park.cpp:135:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
  135 |     scanf("%d %d", &n, &m);
      |     ~~~~~^~~~~~~~~~~~~~~~~
park.cpp:136:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
  136 |     scanf("%d %d", &W, &H);
      |     ~~~~~^~~~~~~~~~~~~~~~~
park.cpp:140:14: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
  140 |         scanf("%d %d %d", &trees[i].x, &trees[i].y, &trees[i].radius);
      |         ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
park.cpp:145:14: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
  145 |         scanf("%d %d", &visitors[j].f.f, &visitors[j].f.s);
      |         ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Subtask #1
27.0 / 27.0

# Verdict Execution time Memory Grader output
1 Correct 286 ms 33280 KB Output is correct
2 Correct 289 ms 33292 KB Output is correct
3 Correct 280 ms 33320 KB Output is correct
4 Correct 263 ms 33344 KB Output is correct
5 Correct 273 ms 33344 KB Output is correct
6 Correct 262 ms 33340 KB Output is correct
7 Correct 284 ms 33344 KB Output is correct
8 Correct 247 ms 33308 KB Output is correct
9 Correct 0 ms 220 KB Output is correct
10 Correct 1 ms 220 KB Output is correct

Subtask #2
31.0 / 31.0

# Verdict Execution time Memory Grader output
1 Correct 99 ms 7788 KB Output is correct
2 Correct 89 ms 7644 KB Output is correct
3 Correct 75 ms 7624 KB Output is correct
4 Correct 75 ms 7640 KB Output is correct
5 Correct 75 ms 7660 KB Output is correct
6 Correct 102 ms 7796 KB Output is correct
7 Correct 77 ms 7392 KB Output is correct
8 Correct 64 ms 8416 KB Output is correct

Subtask #3
42.0 / 42.0

# Verdict Execution time Memory Grader output
1 Correct 286 ms 33280 KB Output is correct
2 Correct 289 ms 33292 KB Output is correct
3 Correct 280 ms 33320 KB Output is correct
4 Correct 263 ms 33344 KB Output is correct
5 Correct 273 ms 33344 KB Output is correct
6 Correct 262 ms 33340 KB Output is correct
7 Correct 284 ms 33344 KB Output is correct
8 Correct 247 ms 33308 KB Output is correct
9 Correct 0 ms 220 KB Output is correct
10 Correct 1 ms 220 KB Output is correct
11 Correct 99 ms 7788 KB Output is correct
12 Correct 89 ms 7644 KB Output is correct
13 Correct 75 ms 7624 KB Output is correct
14 Correct 75 ms 7640 KB Output is correct
15 Correct 75 ms 7660 KB Output is correct
16 Correct 102 ms 7796 KB Output is correct
17 Correct 77 ms 7392 KB Output is correct
18 Correct 64 ms 8416 KB Output is correct
19 Correct 401 ms 39756 KB Output is correct
20 Correct 354 ms 39788 KB Output is correct
21 Correct 401 ms 39748 KB Output is correct
22 Correct 350 ms 39836 KB Output is correct
23 Correct 344 ms 39708 KB Output is correct
24 Correct 360 ms 39776 KB Output is correct