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Submission #1061746

# Submission time Handle Problem Language Result Execution time Memory
1061746 2024-08-16T12:33:13 Z mc061 Fountain Parks (IOI21_parks) C++17
25 / 100
 3500 ms 66796 KB 
#pragma GCC optimize("Ofast")

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

map<pair<int, int>, int> vid;
int di[2] = {2, 0};
int dj[2] = {0, 2};

struct edge {
    int i1, j1, i2, j2;
};

vector<edge> edges;
const int N = 2e5+6;
struct DSU {
    int p[N]={};
    int sz[N];
    DSU() {
        iota(p, p+N, 0);
        fill(sz, sz+N, 1);
    }
    int get(int a) {
        return p[a] = (a == p[a] ? a : get(p[a]));
    }
    void merge(int a, int b) {
        int x = get(a), y = get(b);
        if (x == y) return;
        if (sz[x] > sz[y]) swap(x, y);
        p[x] = y;
        sz[y] += sz[x];
    }
};

vector<edge> horizontal, vertical;

void build(vector<int> u, vector<int> v, vector<int> a, vector<int> b);
bool try_build() {
    // srand(69420);
    //0 - up(hor)   (from road: -1;+1)
    //1 - down(hor) (from road: +1;+1)
    //2 - left(ver) (from road: +1;-1)
    //3 - right(ver)(from road: +1;+1)

    vector<int> tlx = {-1, 1, 1, 1};
    vector<int> tly = {1, 1, -1, 1};

    vector<int> dx = {0, 0, 2, 2};
    vector<int> dy = {2, 2, 0, 0};

    map<pair<int, int>, int> bench_dir;
    for (const auto& e : horizontal) {
        bench_dir[{e.i1-1, e.j1+1}] = 0;
    }
    
    auto sieve_down = [&] (int bi, int bj) -> void {
        bench_dir.erase({bi, bj});
        bi += 2;
        while (bench_dir.count({bi, bj})) {
            bench_dir[{bi, bj}] = 1;
            bi += 2;
        }
        bench_dir[{bi, bj}] = 1;
    };

    for (const auto& e : vertical) {
        int wi_left = e.i1+1;
        int wj_left = e.j1-1;

        int wi_right = e.i1+1;
        int wj_right = e.j1+1;

        if (bench_dir.count({wi_left, wj_left})) {
            if (!bench_dir.count({wi_right, wj_right})) {
                bench_dir[{wi_right, wj_right}] = 3;
                continue;
            }
            int prev_dir = bench_dir[{wi_left, wj_left}];
            
            if (prev_dir == 0) {
                sieve_down(wi_left, wj_left);
                bench_dir[{wi_left, wj_left}] = 2;
                continue;
            }
            if (prev_dir == 1) {
                int prev_dir2 = bench_dir[{wi_right, wj_right}];
                if (prev_dir2 == 1) {
                    return false;
                }
                sieve_down(wi_right, wj_right);
                bench_dir[{wi_right, wj_right}] = 3;
            }
            else if (prev_dir == 3) return false;
        }
        else {
            bench_dir[{wi_left, wj_left}] = 2;
        }
    }
    map<array<int, 4>, pair<int, int>> road_to_bench;
    for (const auto& [x, y] : bench_dir) {         
        int tx = x.first-tlx[y];
        int ty = x.second-tly[y];
        int bx = tx+dx[y];
        int by = ty+dy[y];
        road_to_bench[{tx, ty, bx, by}] = {x.first, x.second};
    }

    vector<int> u, v, a, b;

    for (const auto& e : horizontal) {
        u.push_back(vid[{e.i1, e.j1}]);
        v.push_back(vid[{e.i2, e.j2}]);
        a.push_back(road_to_bench[{e.i1, e.j1, e.i2, e.j2}].first);
        b.push_back(road_to_bench[{e.i1, e.j1, e.i2, e.j2}].second);
    }
    for (const auto& e : vertical) {
        u.push_back(vid[{e.i1, e.j1}]);
        v.push_back(vid[{e.i2, e.j2}]);
        a.push_back(road_to_bench[{e.i1, e.j1, e.i2, e.j2}].first);
        b.push_back(road_to_bench[{e.i1, e.j1, e.i2, e.j2}].second);
    }
    build(u, v, a, b);
    return true;
}

int construct_roads(vector<int> x, vector<int> y) {
    const int n = x.size();
    for (int i = 0; i < n; ++i) {
        vid[{x[i], y[i]}] = i;
    }
    vector<edge> all_vert;
    vector<edge> all_hor;
    for (int i = 0; i < n; ++i) {
        for (int j = 0; j < 2; ++j) {
            int ni = x[i] + di[j];
            int nj = y[i] + dj[j];
            auto it = vid.find({ni, nj});
            if (it == vid.end()) continue;
            edges.push_back({x[i], y[i], ni, nj});
            bool hor = ni == x[i];
            if (!hor) all_vert.push_back({x[i], y[i], ni, nj});
            else all_hor.push_back({x[i], y[i], ni, nj});
        }
    }

    for (int z = 0; z < 20; ++z) {
        random_shuffle(all_hor.begin(), all_hor.end());
        random_shuffle(all_vert.begin(), all_vert.end());
        vertical.clear();
        horizontal.clear();
        DSU d;
        for (const edge& e : all_vert) {
            int id1 = vid[{e.i1, e.j1}];
            int id2 = vid[{e.i2, e.j2}];
            if (d.get(id1) == d.get(id2)) continue;
            d.merge(id1, id2);
            vertical.push_back(e);
        }
        for (const edge& e : all_hor) {
            bool hor = e.i1 == e.i2;
            int id1 = vid[{e.i1, e.j1}];
            int id2 = vid[{e.i2, e.j2}];
            if (d.get(id1) == d.get(id2)) continue;
            d.merge(id1, id2);
            horizontal.push_back(e);
        }
        

        if (d.sz[d.get(0)] != n) return 0;

        sort(vertical.begin(), vertical.end(), [&](const edge& a, const edge& b) {
            if (a.i1 != b.i1) return a.i1 < b.i1;
            return a.j1 < b.j1; 
        });
        int j = try_build();
        if (j == 1) return true;
    }
    return false;
}

Compilation message

parks.cpp: In function 'int construct_roads(std::vector<int>, std::vector<int>)':
parks.cpp:160:18: warning: unused variable 'hor' [-Wunused-variable]
  160 |             bool hor = e.i1 == e.i2;
      |                  ^~~

Subtask #1
5.0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 1884 KB Output is correct
2 Correct 1 ms 1884 KB Output is correct
3 Correct 1 ms 1884 KB Output is correct
4 Correct 1 ms 1884 KB Output is correct
5 Correct 1 ms 1884 KB Output is correct
6 Correct 1 ms 1896 KB Output is correct
7 Correct 1 ms 1884 KB Output is correct
8 Correct 1 ms 1884 KB Output is correct
9 Correct 258 ms 31976 KB Output is correct
10 Correct 18 ms 5076 KB Output is correct
11 Correct 120 ms 17968 KB Output is correct
12 Correct 31 ms 6368 KB Output is correct
13 Correct 38 ms 8296 KB Output is correct
14 Correct 2 ms 2136 KB Output is correct
15 Correct 2 ms 2140 KB Output is correct
16 Correct 260 ms 32056 KB Output is correct

Subtask #2
0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 1884 KB Output is correct
2 Correct 1 ms 1884 KB Output is correct
3 Correct 1 ms 1884 KB Output is correct
4 Correct 1 ms 1884 KB Output is correct
5 Correct 1 ms 1884 KB Output is correct
6 Correct 1 ms 1896 KB Output is correct
7 Correct 1 ms 1884 KB Output is correct
8 Correct 1 ms 1884 KB Output is correct
9 Correct 258 ms 31976 KB Output is correct
10 Correct 18 ms 5076 KB Output is correct
11 Correct 120 ms 17968 KB Output is correct
12 Correct 31 ms 6368 KB Output is correct
13 Correct 38 ms 8296 KB Output is correct
14 Correct 2 ms 2136 KB Output is correct
15 Correct 2 ms 2140 KB Output is correct
16 Correct 260 ms 32056 KB Output is correct
17 Correct 1 ms 1880 KB Output is correct
18 Correct 1 ms 1884 KB Output is correct
19 Correct 1 ms 1884 KB Output is correct
20 Correct 1 ms 1884 KB Output is correct
21 Correct 1 ms 1884 KB Output is correct
22 Correct 1 ms 1884 KB Output is correct
23 Execution timed out 3602 ms 37332 KB Time limit exceeded
24 Halted 0 ms 0 KB -

Subtask #3
0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 1884 KB Output is correct
2 Correct 1 ms 1884 KB Output is correct
3 Correct 1 ms 1884 KB Output is correct
4 Correct 1 ms 1884 KB Output is correct
5 Correct 1 ms 1884 KB Output is correct
6 Correct 1 ms 1896 KB Output is correct
7 Correct 1 ms 1884 KB Output is correct
8 Correct 1 ms 1884 KB Output is correct
9 Correct 258 ms 31976 KB Output is correct
10 Correct 18 ms 5076 KB Output is correct
11 Correct 120 ms 17968 KB Output is correct
12 Correct 31 ms 6368 KB Output is correct
13 Correct 38 ms 8296 KB Output is correct
14 Correct 2 ms 2136 KB Output is correct
15 Correct 2 ms 2140 KB Output is correct
16 Correct 260 ms 32056 KB Output is correct
17 Correct 1 ms 1880 KB Output is correct
18 Correct 1 ms 1884 KB Output is correct
19 Correct 1 ms 1884 KB Output is correct
20 Correct 1 ms 1884 KB Output is correct
21 Correct 1 ms 1884 KB Output is correct
22 Correct 1 ms 1884 KB Output is correct
23 Execution timed out 3602 ms 37332 KB Time limit exceeded
24 Halted 0 ms 0 KB -

Subtask #4
0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 1884 KB Output is correct
2 Correct 1 ms 1884 KB Output is correct
3 Correct 1 ms 1884 KB Output is correct
4 Correct 1 ms 1884 KB Output is correct
5 Correct 1 ms 1884 KB Output is correct
6 Correct 1 ms 1896 KB Output is correct
7 Correct 1 ms 1884 KB Output is correct
8 Correct 1 ms 1884 KB Output is correct
9 Correct 258 ms 31976 KB Output is correct
10 Correct 18 ms 5076 KB Output is correct
11 Correct 120 ms 17968 KB Output is correct
12 Correct 31 ms 6368 KB Output is correct
13 Correct 38 ms 8296 KB Output is correct
14 Correct 2 ms 2136 KB Output is correct
15 Correct 2 ms 2140 KB Output is correct
16 Correct 260 ms 32056 KB Output is correct
17 Correct 1 ms 1884 KB Output is correct
18 Correct 1 ms 1884 KB Output is correct
19 Correct 1 ms 1884 KB Output is correct
20 Correct 577 ms 66796 KB Output is correct
21 Correct 557 ms 63828 KB Output is correct
22 Correct 613 ms 65432 KB Output is correct
23 Correct 421 ms 54832 KB Output is correct
24 Correct 160 ms 17492 KB Output is correct
25 Correct 351 ms 31140 KB Output is correct
26 Correct 280 ms 30372 KB Output is correct
27 Correct 650 ms 64304 KB Output is correct
28 Correct 645 ms 62736 KB Output is correct
29 Correct 565 ms 62808 KB Output is correct
30 Correct 575 ms 62640 KB Output is correct
31 Correct 1 ms 1880 KB Output is correct
32 Correct 28 ms 6408 KB Output is correct
33 Correct 70 ms 9816 KB Output is correct
34 Correct 544 ms 64220 KB Output is correct
35 Correct 10 ms 3236 KB Output is correct
36 Correct 58 ms 8764 KB Output is correct
37 Correct 129 ms 15520 KB Output is correct
38 Incorrect 1047 ms 15196 KB Solution announced impossible, but it is possible.
39 Halted 0 ms 0 KB -

Subtask #5
20.0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 1884 KB Output is correct
2 Correct 1 ms 1884 KB Output is correct
3 Correct 1 ms 1884 KB Output is correct
4 Correct 1 ms 1884 KB Output is correct
5 Correct 1 ms 1884 KB Output is correct
6 Correct 1 ms 1896 KB Output is correct
7 Correct 1 ms 1884 KB Output is correct
8 Correct 1 ms 1884 KB Output is correct
9 Correct 258 ms 31976 KB Output is correct
10 Correct 18 ms 5076 KB Output is correct
11 Correct 120 ms 17968 KB Output is correct
12 Correct 31 ms 6368 KB Output is correct
13 Correct 38 ms 8296 KB Output is correct
14 Correct 2 ms 2136 KB Output is correct
15 Correct 2 ms 2140 KB Output is correct
16 Correct 260 ms 32056 KB Output is correct
17 Correct 565 ms 63728 KB Output is correct
18 Correct 574 ms 65468 KB Output is correct
19 Correct 583 ms 63972 KB Output is correct
20 Correct 653 ms 63664 KB Output is correct
21 Correct 519 ms 57344 KB Output is correct
22 Correct 1 ms 1884 KB Output is correct
23 Correct 69 ms 11748 KB Output is correct
24 Correct 21 ms 4688 KB Output is correct
25 Correct 98 ms 11572 KB Output is correct
26 Correct 186 ms 19636 KB Output is correct
27 Correct 336 ms 33472 KB Output is correct
28 Correct 636 ms 42568 KB Output is correct
29 Correct 1134 ms 50332 KB Output is correct
30 Correct 1053 ms 57456 KB Output is correct
31 Correct 1008 ms 65036 KB Output is correct
32 Correct 698 ms 63804 KB Output is correct
33 Correct 631 ms 62216 KB Output is correct
34 Correct 5 ms 2648 KB Output is correct
35 Correct 8 ms 3288 KB Output is correct
36 Correct 263 ms 32460 KB Output is correct
37 Correct 428 ms 49272 KB Output is correct
38 Correct 610 ms 63172 KB Output is correct

Subtask #6
0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 1884 KB Output is correct
2 Correct 1 ms 1884 KB Output is correct
3 Correct 1 ms 1884 KB Output is correct
4 Correct 1 ms 1884 KB Output is correct
5 Correct 1 ms 1884 KB Output is correct
6 Correct 1 ms 1896 KB Output is correct
7 Correct 1 ms 1884 KB Output is correct
8 Correct 1 ms 1884 KB Output is correct
9 Correct 258 ms 31976 KB Output is correct
10 Correct 18 ms 5076 KB Output is correct
11 Correct 120 ms 17968 KB Output is correct
12 Correct 31 ms 6368 KB Output is correct
13 Correct 38 ms 8296 KB Output is correct
14 Correct 2 ms 2136 KB Output is correct
15 Correct 2 ms 2140 KB Output is correct
16 Correct 260 ms 32056 KB Output is correct
17 Correct 1 ms 1880 KB Output is correct
18 Correct 1 ms 1884 KB Output is correct
19 Correct 1 ms 1884 KB Output is correct
20 Correct 1 ms 1884 KB Output is correct
21 Correct 1 ms 1884 KB Output is correct
22 Correct 1 ms 1884 KB Output is correct
23 Execution timed out 3602 ms 37332 KB Time limit exceeded
24 Halted 0 ms 0 KB -