oj.uz

Submission #800790

# Submission time Handle Problem Language Result Execution time Memory
800790 2023-08-01T20:50:48 Z finn__ Fountain Parks (IOI21_parks) C++17
45 / 100
 288 ms 39644 KB 
#include "parks.h"
#include <bits/stdc++.h>
using namespace std;

template <size_t N>
struct dsu
{
    int64_t p[N];

    dsu() { fill(p, p + N, -1); }

    int64_t repr(int64_t u) { return p[u] < 0 ? u : p[u] = repr(p[u]); }

    bool merge(int64_t i, int64_t j)
    {
        i = repr(i);
        j = repr(j);
        if (i == j)
            return 0;

        if (p[i] > p[j])
            swap(i, j);
        p[i] += p[j];
        p[j] = i;
        return 1;
    }

    bool same_set(int64_t i, int64_t j) { return repr(i) == repr(j); }

    int64_t set_size(int64_t i) { return -p[repr(i)]; }

    void reset() { fill(p.begin(), p.end(), -1); }
};

struct fountain
{
    int x, y;
    size_t i;
};

constexpr size_t N = 200000;

fountain f[N];
vector<pair<size_t, size_t>> edges;
vector<uint32_t> dual[N];
dsu<N> d;
set<pair<int, int>> points, marked;
set<tuple<int, int, uint32_t>> midpoints;
pair<int, int> dual_coords[N];
bitset<N> visited;
size_t l;

void mark_cut_points(uint32_t u)
{
    visited[u] = 1;
    for (auto const &v : dual[u])
        if (!visited[v])
        {
            if (u == l)
            {
                bool placed = 0;
                for (size_t i = 0; i < 4; ++i)
                {
                    pair<int, int> cand = {dual_coords[v].first - 2 + (i & 1) * 4,
                                           dual_coords[v].second - 2 + ((i & 2) >> 1) * 4};
                    bool not_present = 1;
                    for (auto const &w : dual[v])
                        if (w != u)
                            not_present &= dual_coords[w] != cand;
                    if (not_present)
                    {
                        marked.emplace((dual_coords[u].first + cand.first) >> 1,
                                       (dual_coords[u].second + cand.second) >> 1);
                        placed = 1;
                        break;
                    }
                }
                assert(placed);
            }
            else
            {
                marked.emplace((dual_coords[u].first + dual_coords[v].first) >> 1,
                               (dual_coords[u].second + dual_coords[v].second) >> 1);
            }
            mark_cut_points(v);
        }
}

int construct_roads(vector<int> x, vector<int> y)
{
    size_t n = x.size();

    for (size_t i = 0; i < n; ++i)
        points.emplace(x[i], y[i]);
    for (size_t i = 0; i < n; ++i)
        if (points.find({x[i] + 2, y[i]}) != points.end() &&
            points.find({x[i], y[i] + 2}) != points.end() &&
            points.find({x[i] + 2, y[i] + 2}) != points.end())
            midpoints.emplace(x[i] + 1, y[i] + 1, l++), dual_coords[l - 1] = {x[i] + 1, y[i] + 1};
    for (auto const &[x, y, i] : midpoints)
    {
        auto it = midpoints.lower_bound({x + 2, y, 0});
        if (it != midpoints.end() && get<0>(*it) == x + 2 && get<1>(*it) == y)
            dual[i].push_back(get<2>(*it)), dual[get<2>(*it)].push_back(i);
        it = midpoints.lower_bound({x, y + 2, 0});
        if (it != midpoints.end() && get<0>(*it) == x && get<1>(*it) == y + 2)
            dual[i].push_back(get<2>(*it)), dual[get<2>(*it)].push_back(i);
    }
    for (size_t i = 0; i < l; ++i)
        if (dual[i].size() < 4)
            dual[l].push_back(i), dual[i].push_back(l);
    mark_cut_points(l);

    for (size_t i = 0; i < x.size(); ++i)
        f[i].i = i, f[i].x = x[i], f[i].y = y[i];
    sort(f, f + n, [](auto const &a, auto const &b)
         { return a.y == b.y ? a.x < b.x : a.y < b.y; });

    for (size_t i = 0; i < n;)
    {
        size_t j = i;
        while (j < n && f[j].y == f[i].y)
            ++j;

        for (size_t k = i + 1; k < j; ++k)
            if (f[k - 1].x + 2 == f[k].x)
                if (marked.find({f[k - 1].x + 1, f[k - 1].y}) == marked.end() &&
                    d.merge(f[k - 1].i, f[k].i))
                    edges.emplace_back(f[k - 1].i, f[k].i);

        if (f[j].y == f[i].y + 2)
        {
            size_t k = j;
            while (i < j && k < n && f[k].y == f[j].y)
            {
                if (f[i].x < f[k].x)
                    ++i;
                else if (f[k].x < f[i].x)
                    ++k;
                else
                {
                    if (marked.find({f[i].x, f[i].y + 1}) == marked.end() &&
                        d.merge(f[i].i, f[k].i))
                        edges.emplace_back(f[k].i, f[i].i);
                    ++i;
                    ++k;
                }
            }
        }

        i = j;
    }

    if (d.set_size(0) != n)
        return 0;
    vector<int> u, v, a, b;
    for (auto const &[i, j] : edges)
    {
        u.push_back(i);
        v.push_back(j);
        if (x[i] == x[j])
        {
            b.push_back((y[i] + y[j]) >> 1);
            if (((x[i] & 3) == 2) ^ ((min(y[i], y[j]) & 3) == 2))
                a.push_back(x[i] - 1);
            else
                a.push_back(x[i] + 1);
        }
        else
        {
            a.push_back((x[i] + x[j]) >> 1);
            if (((y[i] & 3) == 2) ^ ((min(x[i], x[j]) & 3) == 2))
                b.push_back(y[i] + 1);
            else
                b.push_back(y[i] - 1);
        }
    }

    build(u, v, a, b);
    return 1;
}

Compilation message

parks.cpp: In function 'int construct_roads(std::vector<int>, std::vector<int>)':
parks.cpp:154:23: warning: comparison of integer expressions of different signedness: 'int64_t' {aka 'long int'} and 'size_t' {aka 'long unsigned int'} [-Wsign-compare]
  154 |     if (d.set_size(0) != n)
      |         ~~~~~~~~~~~~~~^~~~

Subtask #1
5.0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 6484 KB Output is correct
2 Correct 2 ms 6484 KB Output is correct
3 Correct 2 ms 6484 KB Output is correct
4 Correct 2 ms 6484 KB Output is correct
5 Correct 3 ms 6484 KB Output is correct
6 Correct 3 ms 6484 KB Output is correct
7 Correct 3 ms 6484 KB Output is correct
8 Correct 3 ms 6484 KB Output is correct
9 Correct 84 ms 22304 KB Output is correct
10 Correct 8 ms 8224 KB Output is correct
11 Correct 40 ms 14868 KB Output is correct
12 Correct 12 ms 8920 KB Output is correct
13 Correct 19 ms 11160 KB Output is correct
14 Correct 3 ms 6612 KB Output is correct
15 Correct 3 ms 6740 KB Output is correct
16 Correct 93 ms 22200 KB Output is correct

Subtask #2
0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 6484 KB Output is correct
2 Correct 2 ms 6484 KB Output is correct
3 Correct 2 ms 6484 KB Output is correct
4 Correct 2 ms 6484 KB Output is correct
5 Correct 3 ms 6484 KB Output is correct
6 Correct 3 ms 6484 KB Output is correct
7 Correct 3 ms 6484 KB Output is correct
8 Correct 3 ms 6484 KB Output is correct
9 Correct 84 ms 22304 KB Output is correct
10 Correct 8 ms 8224 KB Output is correct
11 Correct 40 ms 14868 KB Output is correct
12 Correct 12 ms 8920 KB Output is correct
13 Correct 19 ms 11160 KB Output is correct
14 Correct 3 ms 6612 KB Output is correct
15 Correct 3 ms 6740 KB Output is correct
16 Correct 93 ms 22200 KB Output is correct
17 Incorrect 3 ms 6484 KB Tree @(3, 3) appears more than once: for edges on positions 1 and 2
18 Halted 0 ms 0 KB -

Subtask #3
0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 6484 KB Output is correct
2 Correct 2 ms 6484 KB Output is correct
3 Correct 2 ms 6484 KB Output is correct
4 Correct 2 ms 6484 KB Output is correct
5 Correct 3 ms 6484 KB Output is correct
6 Correct 3 ms 6484 KB Output is correct
7 Correct 3 ms 6484 KB Output is correct
8 Correct 3 ms 6484 KB Output is correct
9 Correct 84 ms 22304 KB Output is correct
10 Correct 8 ms 8224 KB Output is correct
11 Correct 40 ms 14868 KB Output is correct
12 Correct 12 ms 8920 KB Output is correct
13 Correct 19 ms 11160 KB Output is correct
14 Correct 3 ms 6612 KB Output is correct
15 Correct 3 ms 6740 KB Output is correct
16 Correct 93 ms 22200 KB Output is correct
17 Incorrect 3 ms 6484 KB Tree @(3, 3) appears more than once: for edges on positions 1 and 2
18 Halted 0 ms 0 KB -

Subtask #4
20.0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 6484 KB Output is correct
2 Correct 2 ms 6484 KB Output is correct
3 Correct 2 ms 6484 KB Output is correct
4 Correct 2 ms 6484 KB Output is correct
5 Correct 3 ms 6484 KB Output is correct
6 Correct 3 ms 6484 KB Output is correct
7 Correct 3 ms 6484 KB Output is correct
8 Correct 3 ms 6484 KB Output is correct
9 Correct 84 ms 22304 KB Output is correct
10 Correct 8 ms 8224 KB Output is correct
11 Correct 40 ms 14868 KB Output is correct
12 Correct 12 ms 8920 KB Output is correct
13 Correct 19 ms 11160 KB Output is correct
14 Correct 3 ms 6612 KB Output is correct
15 Correct 3 ms 6740 KB Output is correct
16 Correct 93 ms 22200 KB Output is correct
17 Correct 3 ms 6484 KB Output is correct
18 Correct 3 ms 6484 KB Output is correct
19 Correct 3 ms 6484 KB Output is correct
20 Correct 262 ms 39024 KB Output is correct
21 Correct 257 ms 38856 KB Output is correct
22 Correct 253 ms 38836 KB Output is correct
23 Correct 190 ms 34336 KB Output is correct
24 Correct 141 ms 22224 KB Output is correct
25 Correct 238 ms 26428 KB Output is correct
26 Correct 153 ms 26432 KB Output is correct
27 Correct 203 ms 38540 KB Output is correct
28 Correct 213 ms 38176 KB Output is correct
29 Correct 271 ms 38160 KB Output is correct
30 Correct 288 ms 38168 KB Output is correct
31 Correct 3 ms 6484 KB Output is correct
32 Correct 16 ms 8948 KB Output is correct
33 Correct 67 ms 14392 KB Output is correct
34 Correct 225 ms 39108 KB Output is correct
35 Correct 9 ms 7640 KB Output is correct
36 Correct 42 ms 11640 KB Output is correct
37 Correct 90 ms 16532 KB Output is correct
38 Correct 98 ms 19808 KB Output is correct
39 Correct 131 ms 24152 KB Output is correct
40 Correct 173 ms 30160 KB Output is correct
41 Correct 246 ms 34340 KB Output is correct
42 Correct 281 ms 39644 KB Output is correct
43 Correct 3 ms 6484 KB Output is correct
44 Correct 3 ms 6528 KB Output is correct
45 Correct 3 ms 6484 KB Output is correct
46 Correct 3 ms 6484 KB Output is correct
47 Correct 4 ms 6572 KB Output is correct
48 Correct 3 ms 6484 KB Output is correct
49 Correct 3 ms 6484 KB Output is correct
50 Correct 3 ms 6484 KB Output is correct
51 Correct 3 ms 6492 KB Output is correct
52 Correct 3 ms 6484 KB Output is correct
53 Correct 3 ms 6484 KB Output is correct
54 Correct 3 ms 6740 KB Output is correct
55 Correct 4 ms 6868 KB Output is correct
56 Correct 99 ms 22276 KB Output is correct
57 Correct 148 ms 30140 KB Output is correct
58 Correct 152 ms 30284 KB Output is correct
59 Correct 3 ms 6484 KB Output is correct
60 Correct 3 ms 6532 KB Output is correct
61 Correct 3 ms 6484 KB Output is correct
62 Correct 174 ms 38172 KB Output is correct
63 Correct 182 ms 38196 KB Output is correct
64 Correct 171 ms 38016 KB Output is correct
65 Correct 5 ms 6996 KB Output is correct
66 Correct 7 ms 7380 KB Output is correct
67 Correct 103 ms 22148 KB Output is correct
68 Correct 160 ms 30896 KB Output is correct
69 Correct 222 ms 38108 KB Output is correct

Subtask #5
20.0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 6484 KB Output is correct
2 Correct 2 ms 6484 KB Output is correct
3 Correct 2 ms 6484 KB Output is correct
4 Correct 2 ms 6484 KB Output is correct
5 Correct 3 ms 6484 KB Output is correct
6 Correct 3 ms 6484 KB Output is correct
7 Correct 3 ms 6484 KB Output is correct
8 Correct 3 ms 6484 KB Output is correct
9 Correct 84 ms 22304 KB Output is correct
10 Correct 8 ms 8224 KB Output is correct
11 Correct 40 ms 14868 KB Output is correct
12 Correct 12 ms 8920 KB Output is correct
13 Correct 19 ms 11160 KB Output is correct
14 Correct 3 ms 6612 KB Output is correct
15 Correct 3 ms 6740 KB Output is correct
16 Correct 93 ms 22200 KB Output is correct
17 Correct 218 ms 38564 KB Output is correct
18 Correct 209 ms 38668 KB Output is correct
19 Correct 245 ms 38872 KB Output is correct
20 Correct 261 ms 37484 KB Output is correct
21 Correct 210 ms 34332 KB Output is correct
22 Correct 3 ms 6484 KB Output is correct
23 Correct 34 ms 11792 KB Output is correct
24 Correct 17 ms 8784 KB Output is correct
25 Correct 61 ms 14200 KB Output is correct
26 Correct 109 ms 18052 KB Output is correct
27 Correct 118 ms 22652 KB Output is correct
28 Correct 165 ms 26712 KB Output is correct
29 Correct 184 ms 31844 KB Output is correct
30 Correct 239 ms 35252 KB Output is correct
31 Correct 268 ms 39020 KB Output is correct
32 Correct 218 ms 38080 KB Output is correct
33 Correct 178 ms 38160 KB Output is correct
34 Correct 5 ms 7124 KB Output is correct
35 Correct 7 ms 7636 KB Output is correct
36 Correct 103 ms 22400 KB Output is correct
37 Correct 165 ms 30928 KB Output is correct
38 Correct 220 ms 38216 KB Output is correct

Subtask #6
0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 6484 KB Output is correct
2 Correct 2 ms 6484 KB Output is correct
3 Correct 2 ms 6484 KB Output is correct
4 Correct 2 ms 6484 KB Output is correct
5 Correct 3 ms 6484 KB Output is correct
6 Correct 3 ms 6484 KB Output is correct
7 Correct 3 ms 6484 KB Output is correct
8 Correct 3 ms 6484 KB Output is correct
9 Correct 84 ms 22304 KB Output is correct
10 Correct 8 ms 8224 KB Output is correct
11 Correct 40 ms 14868 KB Output is correct
12 Correct 12 ms 8920 KB Output is correct
13 Correct 19 ms 11160 KB Output is correct
14 Correct 3 ms 6612 KB Output is correct
15 Correct 3 ms 6740 KB Output is correct
16 Correct 93 ms 22200 KB Output is correct
17 Incorrect 3 ms 6484 KB Tree @(3, 3) appears more than once: for edges on positions 1 and 2
18 Halted 0 ms 0 KB -