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Submission #932692

# Submission time Handle Problem Language Result Execution time Memory
932692 2024-02-24T03:17:09 Z Programmer123 Fountain Parks (IOI21_parks) C++17
15 / 100
 3500 ms 133756 KB 
#ifndef LOCAL
#pragma GCC optimize("Ofast")
#pragma GCC target("avx2,sse4.2")
#endif

#include <bits/stdc++.h>
#include "parks.h"

std::unordered_map<int, int> map[100001];
int N;
std::unordered_map<int, std::vector<int>> rely[100002];
std::vector<std::pair<int, int>> vld[200000];
std::pair<int, int> assigned[200000];
std::unordered_set<int> taken[100002];
time_t stop;
std::default_random_engine Rand(std::random_device{}());

bool shuffle = true;
bool Shuffle = false;

bool doomed(int x) {
    for (auto a: vld[x]) if (!taken[a.first / 2].count(a.second)) return false;
    return true;
}

bool cantake(std::pair<int, int> a, int n) {
    for (auto x: rely[a.first / 2][a.second]) if (x > n && doomed(x)) return false;
    return true;
}

#ifdef LOCAL
size_t called = 0;
#endif

bool backtrack(int n) {
#ifdef LOCAL
    called++;
#endif
    if (n == N - 1) return true;
    if (clock() > stop) return false;
//    if (Shuffle && vld[n].size() == 2 && Rand() % 2) {
//        std::swap(vld[n][0], vld[n][1]);
//    }
    for (auto a: vld[n]) {
        if (taken[a.first / 2].count(a.second)) continue;
        taken[a.first / 2].insert(a.second);
        if (!cantake(a, n)) {
            taken[a.first / 2].erase(a.second);
            continue;
        }
        if (backtrack(n + 1)) {
            assigned[n] = a;
            return true;
        }
        taken[a.first / 2].erase(a.second);
    }
    return false;
}

int construct_roads(std::vector<int> x, std::vector<int> y) {
    stop = clock() + 3.4 * CLOCKS_PER_SEC;
    N = (int) x.size();
    if (N == 1) {
        build({}, {}, {}, {});
        return 1;
    }
    int maxx = x[0];
    int minx = x[0];
    int maxy = y[0];
    int miny = y[0];
    for (int i = 0; i < N; ++i) {
        maxx = std::max(maxx, x[i]);
        minx = std::min(minx, x[i]);
        maxy = std::max(maxy, y[i]);
        miny = std::min(miny, y[i]);
    }
    for (int i = 0; i < N; ++i) {
        map[x[i] / 2][y[i]] = i;
    }
    while (true) {
        std::vector<int> u, v, a, b;
        bool seen[N];
        for (int i = 0; i < N; ++i) {
            seen[i] = false;
        }
        std::queue<int> bfs;
        int start = 0;
        if (shuffle) {
            for (int i = 0; i < N; ++i) {
                if (x[i] < x[start]) start = i;
                if (x[i] == x[start] && y[i] < y[start]) start = i;
            }
        }
        if (Shuffle) {
            start = Rand() % N;
        }
        bfs.push(start);
        seen[start] = true;
        auto add = [&](int x, int y, std::vector<int> &data) {
            if (x < 0 || x > 200000) return;
            if (map[x / 2].count(y)) data.push_back(map[x / 2][y]);
        };
        auto edges = [&](int x, int y) {
            std::vector<int> result;
            add(x, y + 2, result);
            add(x, y - 2, result);
            add(x + 2, y, result);
            add(x - 2, y, result);
            if (Shuffle) {
                std::shuffle(result.begin(), result.end(), Rand);
            }
            return result;
        };
        int rem = N - 1;
        while (!bfs.empty()) {
            auto next = bfs.front();
            bfs.pop();
            for (auto n: edges(x[next], y[next])) {
                if (!seen[n]) {
                    seen[n] = true;
                    bfs.push(n);
                    rem--;
                    u.push_back(next);
                    v.push_back(n);
                }
            }
        }
        if (rem)
            return 0;

        std::function<std::vector<std::pair<int, int>>(int, int)> valid = [&x, &y, minx, maxx, miny, maxy](int u,
                                                                                                           int v) -> std::vector<std::pair<int, int>> {
            if (x[u] == x[v]) {
                int _y = (y[u] + y[v]) / 2;
                if (x[u] == minx) return {{minx - 1, _y}};
                if (x[u] == maxx) return {{maxx + 1, _y}};
                return {{x[u] + 1, _y},
                        {x[u] - 1, _y}};
            } else {
                int _x = (x[u] + x[v]) / 2;
                if (y[u] == miny) return {{_x, miny - 1}};
                if (y[u] == maxy) return {{_x, maxy + 1}};
                return {{_x, y[u] + 1},
                        {_x, y[u] - 1}};
            }
        };
        if (shuffle) {
            std::vector<std::pair<int, int>> Edges;
            for (int i = 0; i < N - 1; ++i) {
                Edges.emplace_back(u[i], v[i]);
            }
            std::sort(Edges.begin(), Edges.end(), [&](std::pair<int, int> a, std::pair<int, int> b) {
                int A = a.first;
                int B = b.first;
                if (x[A] == x[B]) return y[A] < y[B];
                return x[A] < x[B];
            });
            for (int i = 0; i < N - 1; ++i) {
                u[i] = Edges[i].first;
                v[i] = Edges[i].second;
            }
        }
        for (int i = 0; i < N - 1; ++i) {
            vld[i] = valid(u[i], v[i]);
            if (Shuffle && vld[i].size() == 2 && Rand() % 2) {
                std::swap(vld[i][0], vld[i][1]);
            }
        }
        for (int i = 0; i < N - 1; ++i) {
            for (auto n: vld[i]) {
                rely[n.first / 2][n.second].push_back(i);
            }
        }
        if (shuffle && !Shuffle)
            stop = clock() + CLOCKS_PER_SEC;
        if (backtrack(0)) {
#ifdef LOCAL
            printf("Called backtrack %ld times.\n", called);
            called = 0;
#endif
            for (int i = 0; i < N - 1; ++i) {
                a.push_back(assigned[i].first);
                b.push_back(assigned[i].second);
            }
            build(u, v, a, b);
            return 1;
        }
#ifdef LOCAL
        printf("Called backtrack %ld times.\n", called);
        called = 0;
#endif
        for (auto _x: x) {
            rely[(_x - 1) / 2].clear();
            rely[(_x + 1) / 2].clear();
        }
        if (shuffle && !Shuffle) {
            shuffle = false;
        } else if (!(shuffle || Shuffle)) {
            Shuffle = true;
        } else {
            shuffle = true;
        }
#ifdef LOCAL
        printf("Retrying...\n");
#endif
    }
    return 0;
}

Subtask #1
5.0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 6 ms 23132 KB Output is correct
2 Correct 6 ms 23132 KB Output is correct
3 Correct 6 ms 23132 KB Output is correct
4 Correct 6 ms 23132 KB Output is correct
5 Correct 7 ms 23132 KB Output is correct
6 Correct 7 ms 23132 KB Output is correct
7 Correct 7 ms 23132 KB Output is correct
8 Correct 7 ms 23136 KB Output is correct
9 Correct 142 ms 66568 KB Output is correct
10 Correct 19 ms 27204 KB Output is correct
11 Correct 74 ms 46184 KB Output is correct
12 Correct 25 ms 29472 KB Output is correct
13 Correct 19 ms 26148 KB Output is correct
14 Correct 7 ms 23132 KB Output is correct
15 Correct 7 ms 23132 KB Output is correct
16 Correct 146 ms 66704 KB Output is correct

Subtask #2
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 6 ms 23132 KB Output is correct
2 Correct 6 ms 23132 KB Output is correct
3 Correct 6 ms 23132 KB Output is correct
4 Correct 6 ms 23132 KB Output is correct
5 Correct 7 ms 23132 KB Output is correct
6 Correct 7 ms 23132 KB Output is correct
7 Correct 7 ms 23132 KB Output is correct
8 Correct 7 ms 23136 KB Output is correct
9 Correct 142 ms 66568 KB Output is correct
10 Correct 19 ms 27204 KB Output is correct
11 Correct 74 ms 46184 KB Output is correct
12 Correct 25 ms 29472 KB Output is correct
13 Correct 19 ms 26148 KB Output is correct
14 Correct 7 ms 23132 KB Output is correct
15 Correct 7 ms 23132 KB Output is correct
16 Correct 146 ms 66704 KB Output is correct
17 Correct 6 ms 23132 KB Output is correct
18 Correct 6 ms 23132 KB Output is correct
19 Correct 6 ms 23128 KB Output is correct
20 Correct 7 ms 23132 KB Output is correct
21 Correct 7 ms 23132 KB Output is correct
22 Correct 7 ms 23132 KB Output is correct
23 Correct 320 ms 108836 KB Output is correct
24 Correct 6 ms 23132 KB Output is correct
25 Correct 8 ms 23644 KB Output is correct
26 Correct 8 ms 23132 KB Output is correct
27 Correct 8 ms 23132 KB Output is correct
28 Correct 119 ms 55728 KB Output is correct
29 Correct 180 ms 73868 KB Output is correct
30 Correct 240 ms 88240 KB Output is correct
31 Correct 305 ms 108500 KB Output is correct
32 Correct 8 ms 23128 KB Output is correct
33 Correct 7 ms 23132 KB Output is correct
34 Correct 7 ms 23132 KB Output is correct
35 Correct 7 ms 22956 KB Output is correct
36 Correct 7 ms 23132 KB Output is correct
37 Correct 6 ms 23132 KB Output is correct
38 Correct 7 ms 23128 KB Output is correct
39 Correct 6 ms 23132 KB Output is correct
40 Correct 6 ms 23132 KB Output is correct
41 Correct 7 ms 23132 KB Output is correct
42 Correct 8 ms 23132 KB Output is correct
43 Correct 7 ms 23132 KB Output is correct
44 Correct 7 ms 23132 KB Output is correct
45 Correct 169 ms 68284 KB Output is correct
46 Correct 263 ms 88852 KB Output is correct
47 Correct 266 ms 88768 KB Output is correct

Subtask #3
0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 6 ms 23132 KB Output is correct
2 Correct 6 ms 23132 KB Output is correct
3 Correct 6 ms 23132 KB Output is correct
4 Correct 6 ms 23132 KB Output is correct
5 Correct 7 ms 23132 KB Output is correct
6 Correct 7 ms 23132 KB Output is correct
7 Correct 7 ms 23132 KB Output is correct
8 Correct 7 ms 23136 KB Output is correct
9 Correct 142 ms 66568 KB Output is correct
10 Correct 19 ms 27204 KB Output is correct
11 Correct 74 ms 46184 KB Output is correct
12 Correct 25 ms 29472 KB Output is correct
13 Correct 19 ms 26148 KB Output is correct
14 Correct 7 ms 23132 KB Output is correct
15 Correct 7 ms 23132 KB Output is correct
16 Correct 146 ms 66704 KB Output is correct
17 Correct 6 ms 23132 KB Output is correct
18 Correct 6 ms 23132 KB Output is correct
19 Correct 6 ms 23128 KB Output is correct
20 Correct 7 ms 23132 KB Output is correct
21 Correct 7 ms 23132 KB Output is correct
22 Correct 7 ms 23132 KB Output is correct
23 Correct 320 ms 108836 KB Output is correct
24 Correct 6 ms 23132 KB Output is correct
25 Correct 8 ms 23644 KB Output is correct
26 Correct 8 ms 23132 KB Output is correct
27 Correct 8 ms 23132 KB Output is correct
28 Correct 119 ms 55728 KB Output is correct
29 Correct 180 ms 73868 KB Output is correct
30 Correct 240 ms 88240 KB Output is correct
31 Correct 305 ms 108500 KB Output is correct
32 Correct 8 ms 23128 KB Output is correct
33 Correct 7 ms 23132 KB Output is correct
34 Correct 7 ms 23132 KB Output is correct
35 Correct 7 ms 22956 KB Output is correct
36 Correct 7 ms 23132 KB Output is correct
37 Correct 6 ms 23132 KB Output is correct
38 Correct 7 ms 23128 KB Output is correct
39 Correct 6 ms 23132 KB Output is correct
40 Correct 6 ms 23132 KB Output is correct
41 Correct 7 ms 23132 KB Output is correct
42 Correct 8 ms 23132 KB Output is correct
43 Correct 7 ms 23132 KB Output is correct
44 Correct 7 ms 23132 KB Output is correct
45 Correct 169 ms 68284 KB Output is correct
46 Correct 263 ms 88852 KB Output is correct
47 Correct 266 ms 88768 KB Output is correct
48 Correct 8 ms 23132 KB Output is correct
49 Correct 6 ms 23132 KB Output is correct
50 Correct 7 ms 23132 KB Output is correct
51 Correct 7 ms 23132 KB Output is correct
52 Correct 7 ms 22964 KB Output is correct
53 Correct 8 ms 23132 KB Output is correct
54 Correct 7 ms 22960 KB Output is correct
55 Correct 316 ms 105992 KB Output is correct
56 Correct 7 ms 23384 KB Output is correct
57 Correct 75 ms 23792 KB Output is correct
58 Correct 16 ms 25692 KB Output is correct
59 Correct 9 ms 23640 KB Output is correct
60 Execution timed out 3543 ms 59860 KB Time limit exceeded
61 Halted 0 ms 0 KB -

Subtask #4
0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 6 ms 23132 KB Output is correct
2 Correct 6 ms 23132 KB Output is correct
3 Correct 6 ms 23132 KB Output is correct
4 Correct 6 ms 23132 KB Output is correct
5 Correct 7 ms 23132 KB Output is correct
6 Correct 7 ms 23132 KB Output is correct
7 Correct 7 ms 23132 KB Output is correct
8 Correct 7 ms 23136 KB Output is correct
9 Correct 142 ms 66568 KB Output is correct
10 Correct 19 ms 27204 KB Output is correct
11 Correct 74 ms 46184 KB Output is correct
12 Correct 25 ms 29472 KB Output is correct
13 Correct 19 ms 26148 KB Output is correct
14 Correct 7 ms 23132 KB Output is correct
15 Correct 7 ms 23132 KB Output is correct
16 Correct 146 ms 66704 KB Output is correct
17 Correct 7 ms 23132 KB Output is correct
18 Correct 7 ms 23128 KB Output is correct
19 Correct 7 ms 23132 KB Output is correct
20 Correct 394 ms 133756 KB Output is correct
21 Correct 328 ms 117232 KB Output is correct
22 Correct 393 ms 117252 KB Output is correct
23 Correct 311 ms 109696 KB Output is correct
24 Correct 60 ms 34388 KB Output is correct
25 Correct 59 ms 34388 KB Output is correct
26 Correct 60 ms 34384 KB Output is correct
27 Correct 351 ms 122568 KB Output is correct
28 Correct 369 ms 122468 KB Output is correct
29 Correct 368 ms 124052 KB Output is correct
30 Correct 371 ms 124112 KB Output is correct
31 Correct 7 ms 23132 KB Output is correct
32 Execution timed out 3506 ms 26756 KB Time limit exceeded
33 Halted 0 ms 0 KB -

Subtask #5
0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 6 ms 23132 KB Output is correct
2 Correct 6 ms 23132 KB Output is correct
3 Correct 6 ms 23132 KB Output is correct
4 Correct 6 ms 23132 KB Output is correct
5 Correct 7 ms 23132 KB Output is correct
6 Correct 7 ms 23132 KB Output is correct
7 Correct 7 ms 23132 KB Output is correct
8 Correct 7 ms 23136 KB Output is correct
9 Correct 142 ms 66568 KB Output is correct
10 Correct 19 ms 27204 KB Output is correct
11 Correct 74 ms 46184 KB Output is correct
12 Correct 25 ms 29472 KB Output is correct
13 Correct 19 ms 26148 KB Output is correct
14 Correct 7 ms 23132 KB Output is correct
15 Correct 7 ms 23132 KB Output is correct
16 Correct 146 ms 66704 KB Output is correct
17 Correct 365 ms 121252 KB Output is correct
18 Correct 391 ms 129872 KB Output is correct
19 Correct 364 ms 117316 KB Output is correct
20 Correct 358 ms 108988 KB Output is correct
21 Correct 355 ms 110460 KB Output is correct
22 Correct 7 ms 23384 KB Output is correct
23 Execution timed out 3573 ms 30792 KB Time limit exceeded
24 Halted 0 ms 0 KB -

Subtask #6
0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 6 ms 23132 KB Output is correct
2 Correct 6 ms 23132 KB Output is correct
3 Correct 6 ms 23132 KB Output is correct
4 Correct 6 ms 23132 KB Output is correct
5 Correct 7 ms 23132 KB Output is correct
6 Correct 7 ms 23132 KB Output is correct
7 Correct 7 ms 23132 KB Output is correct
8 Correct 7 ms 23136 KB Output is correct
9 Correct 142 ms 66568 KB Output is correct
10 Correct 19 ms 27204 KB Output is correct
11 Correct 74 ms 46184 KB Output is correct
12 Correct 25 ms 29472 KB Output is correct
13 Correct 19 ms 26148 KB Output is correct
14 Correct 7 ms 23132 KB Output is correct
15 Correct 7 ms 23132 KB Output is correct
16 Correct 146 ms 66704 KB Output is correct
17 Correct 6 ms 23132 KB Output is correct
18 Correct 6 ms 23132 KB Output is correct
19 Correct 6 ms 23128 KB Output is correct
20 Correct 7 ms 23132 KB Output is correct
21 Correct 7 ms 23132 KB Output is correct
22 Correct 7 ms 23132 KB Output is correct
23 Correct 320 ms 108836 KB Output is correct
24 Correct 6 ms 23132 KB Output is correct
25 Correct 8 ms 23644 KB Output is correct
26 Correct 8 ms 23132 KB Output is correct
27 Correct 8 ms 23132 KB Output is correct
28 Correct 119 ms 55728 KB Output is correct
29 Correct 180 ms 73868 KB Output is correct
30 Correct 240 ms 88240 KB Output is correct
31 Correct 305 ms 108500 KB Output is correct
32 Correct 8 ms 23128 KB Output is correct
33 Correct 7 ms 23132 KB Output is correct
34 Correct 7 ms 23132 KB Output is correct
35 Correct 7 ms 22956 KB Output is correct
36 Correct 7 ms 23132 KB Output is correct
37 Correct 6 ms 23132 KB Output is correct
38 Correct 7 ms 23128 KB Output is correct
39 Correct 6 ms 23132 KB Output is correct
40 Correct 6 ms 23132 KB Output is correct
41 Correct 7 ms 23132 KB Output is correct
42 Correct 8 ms 23132 KB Output is correct
43 Correct 7 ms 23132 KB Output is correct
44 Correct 7 ms 23132 KB Output is correct
45 Correct 169 ms 68284 KB Output is correct
46 Correct 263 ms 88852 KB Output is correct
47 Correct 266 ms 88768 KB Output is correct
48 Correct 8 ms 23132 KB Output is correct
49 Correct 6 ms 23132 KB Output is correct
50 Correct 7 ms 23132 KB Output is correct
51 Correct 7 ms 23132 KB Output is correct
52 Correct 7 ms 22964 KB Output is correct
53 Correct 8 ms 23132 KB Output is correct
54 Correct 7 ms 22960 KB Output is correct
55 Correct 316 ms 105992 KB Output is correct
56 Correct 7 ms 23384 KB Output is correct
57 Correct 75 ms 23792 KB Output is correct
58 Correct 16 ms 25692 KB Output is correct
59 Correct 9 ms 23640 KB Output is correct
60 Execution timed out 3543 ms 59860 KB Time limit exceeded
61 Halted 0 ms 0 KB -