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Submission #1058384

# Submission time Handle Problem Language Result Execution time Memory
1058384 2024-08-14T09:42:20 Z vjudge1 Fountain Parks (IOI21_parks) C++17
15 / 100
 3500 ms 164568 KB 
#include "parks.h"
#include <bits/stdc++.h>

using namespace std;

using vi = vector<int>;
using ii = pair<int, int>;

int DX[] = {-1, 0, 1, 0};
int DY[] = {0, 1, 0, -1};

struct DSU {
    int nrc;
    vi e;
    DSU(int n) : nrc(n), e(n, -1) {}
    int repr(int u) {
        while(e[u] >= 0) u = e[u];
        return u;
    }

    bool same(int u, int v) { return repr(u) == repr(v); }

    void join(int u, int v) {
        u = repr(u);
        v = repr(v);
        if(u == v) return;
        --nrc;
        if(e[u] >= e[v]) swap(u, v);
        e[u] += e[v];
        e[v] = u;
    }
};

vi solve_assign(int m, int len, vector<vector<ii> > &G0, bool &ok) {
    /// will return a vector of len elements, with the id of the bench assigned to path i
    vector<set<ii> > G(m);
    for(int i = 0; i < m; ++i) {
        for(auto it : G0[i]) G[i].insert(it);
    }
   // printf("m=%d len=%d\n", m, len);
   // for(int i = 0; i < m; ++i) {
   //     printf("G[%d]: ", i);
   //     for(auto [a, b] : G[i]) printf("(%d, %d) ", a, b);
   //     printf("\n");
   // }
   // printf("\n");
    vi Re(len, -1);
    
    set<int> noduri_singure;
    for(int i = 0; i < m; ++i) {
        if(G[i].size() == 1) {
            noduri_singure.insert(i);
        }
    }
    while(!noduri_singure.empty()) {
        auto u = *noduri_singure.begin();
        noduri_singure.erase(u);
        if(G[u].empty()) continue;

        /// am muchia u<->v, care se refera la drumul cul
        auto [v, cul] = *G[u].begin(); 

        Re[cul] = u;
        G[v].erase({u, cul});
        G[u].clear();
        if(G[v].size() == 1) noduri_singure.insert(v);
    }


    ///fiecare nod are outdeg > 1 acum
    ///ar trebuii sa fi ramas doar cu un ciclu

    vi viz(m, 0);
    function<void(int, int)> dfs = [&](int u, int p) {
        for(auto [v, cul] : G[u]) {
            if(v == p) continue;
            if(!viz[v]) {
                viz[v] = 1;
                Re[cul] = v;
                dfs(v, u);
            }
            if(viz[u]) break;
        }
    };
    for(int i = 0; i < m; ++i) {
        if(G[i].size() > 1) {
            dfs(i, -1);
            break;
        }
    }
  //  printf("Re: ");
  //  for(auto it : Re) {
  //      printf("%d ", it);
  //  }
  //  printf("\n");
    for(auto it : Re) if(it == -1) ok = 0;
    return Re;
}


int try_construct(vi x, vi y) {
    int n = (int)x.size();
    map<ii, int> Id;
    for(int i = 0; i < n; ++i)
        Id[ii{x[i], y[i]}] = i;
    auto get_bs_coord = [&](int u, int v) -> pair<ii, ii> {
        int x1 = x[u], y1 = y[u], x2 = x[v], y2 = y[v];
        int xcm = (x1 + x2) / 2, ycm = (y1 + y2) / 2;
        int dx = 2 - abs(x1 - x2), dy = 2 - abs(y1 - y2);
        assert(dx >= 0 && dy >= 0); // alaturate
        return make_pair(ii{xcm + dx / 2, ycm + dy / 2}, ii{xcm - dx / 2, ycm - dy / 2});
    };
    vector<ii> B;
    for(int i = 0; i < n; ++i) {
        for(int d = 0; d < 4; ++d) {
            int nx = x[i] + DX[d] * 2, ny = y[i] + DY[d] * 2;
            if(Id.count({nx, ny})) {
                int u = Id[ii{nx, ny}];
                auto [a, b] = get_bs_coord(i, u);
                assert(a.first & 1);
                assert(a.second & 1);
                assert(b.first & 1);
                assert(b.second & 1);
                B.push_back(a);
                B.push_back(b);
            }
        }
    }

    sort(B.begin(), B.end());
    B.resize(unique(B.begin(), B.end()) - B.begin());

    map<ii, int> BenchId;
    int m = (int)B.size();

    vector<vi> L(n); /// graful pe fantani
    vector<ii> E; // edges
    set<ii> SetEdges;
    vector<vector<ii> > G(m); /// graful pe banci
    for(int i = 0; i < B.size(); ++i)
        BenchId[B[i]] = i;
    
    auto get_bs_id = [&](int u, int v) {
        auto [a, b] = get_bs_coord(u, v);
        return ii{BenchId[a], BenchId[b]};
    };

    vector<ii> DupaY;
    for(int i = 0; i < n; ++i)
        DupaY.push_back({y[i], i});
    sort(DupaY.begin(), DupaY.end());

    vi Speciale = {DupaY[0].second};

    DSU UF(n);

    auto add_edge = [&](int u, int v) {
        if(SetEdges.count({u, v})) return;
        if(UF.same(u, v)) return;
        SetEdges.insert({u, v});
        SetEdges.insert({v, u});
        auto [a, b] = get_bs_id(u, v);
        G[a].push_back({b, E.size()});
        G[b].push_back({a, E.size()});
        L[u].push_back(v);
        L[v].push_back(u);
        E.push_back({u, v});
        UF.join(u, v);
    };

    for(int i = 1; i < n; ++i) {
        int u = DupaY[i - 1].second, v = DupaY[i].second;
        if(y[u] != y[v] || abs(x[u] - x[v]) > 2) {
            Speciale.push_back(v);
            Speciale.push_back(u);
        }
        else add_edge(u, v);
    }

    static mt19937 rng(1);
    auto nr = [&](int a, int b) { return uniform_int_distribution<int>(a, b)(rng); };

    shuffle(Speciale.begin(), Speciale.end(), rng);
    for(auto it : Speciale) {
        for(int d = 0; d < 4; ++d) {
            int nx = x[it] + DX[d] * 2, ny = y[it] + DY[d] * 2;
            if(Id.count({nx, ny})) {
                int u = Id[ii{nx, ny}];
                add_edge(it, u);
            }
        }
    }

    if(UF.nrc != 1) return 0;

   // printf("muchile pe fantani:\n");
   // for(auto [u, v] : E) {
   //     printf("%d %d\n", u, v);
   // }
   // printf("\n");

    bool ok = 1;
    auto Re = solve_assign(m, E.size(), G, ok);
    if(!ok) return 0;

    int len = E.size();
    vi U(len), V(len), RA(len), RB(len);
    for(int i = 0; i < len; ++i) {
        tie(U[i], V[i]) = E[i];
        int id = Re[i];
        assert(id >= 0 && id < B.size());
        tie(RA[i], RB[i]) = B[id];
    }

    build(U, V, RA, RB);
    return 1;
}
int construct_roads(vi x, vi y) {
    for(int i = 0; i < 10; ++i) {
        if(try_construct(x, y)) return 1;
    }
    return 0;
}

Compilation message

parks.cpp: In function 'int try_construct(vi, vi)':
parks.cpp:140:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  140 |     for(int i = 0; i < B.size(); ++i)
      |                    ~~^~~~~~~~~~
In file included from /usr/include/c++/10/cassert:44,
                 from /usr/include/x86_64-linux-gnu/c++/10/bits/stdc++.h:33,
                 from parks.cpp:2:
parks.cpp:211:30: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  211 |         assert(id >= 0 && id < B.size());
      |                           ~~~^~~~~~~~~~
parks.cpp:181:10: warning: variable 'nr' set but not used [-Wunused-but-set-variable]
  181 |     auto nr = [&](int a, int b) { return uniform_int_distribution<int>(a, b)(rng); };
      |          ^~

Subtask #1
5.0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 344 KB Output is correct
2 Correct 0 ms 348 KB Output is correct
3 Correct 0 ms 348 KB Output is correct
4 Correct 0 ms 348 KB Output is correct
5 Correct 0 ms 348 KB Output is correct
6 Correct 0 ms 348 KB Output is correct
7 Correct 0 ms 348 KB Output is correct
8 Correct 0 ms 348 KB Output is correct
9 Correct 676 ms 81768 KB Output is correct
10 Correct 35 ms 8392 KB Output is correct
11 Correct 274 ms 44244 KB Output is correct
12 Correct 60 ms 12484 KB Output is correct
13 Correct 1576 ms 25044 KB Output is correct
14 Correct 19 ms 860 KB Output is correct
15 Correct 45 ms 1484 KB Output is correct
16 Correct 681 ms 82360 KB Output is correct

Subtask #2
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 344 KB Output is correct
2 Correct 0 ms 348 KB Output is correct
3 Correct 0 ms 348 KB Output is correct
4 Correct 0 ms 348 KB Output is correct
5 Correct 0 ms 348 KB Output is correct
6 Correct 0 ms 348 KB Output is correct
7 Correct 0 ms 348 KB Output is correct
8 Correct 0 ms 348 KB Output is correct
9 Correct 676 ms 81768 KB Output is correct
10 Correct 35 ms 8392 KB Output is correct
11 Correct 274 ms 44244 KB Output is correct
12 Correct 60 ms 12484 KB Output is correct
13 Correct 1576 ms 25044 KB Output is correct
14 Correct 19 ms 860 KB Output is correct
15 Correct 45 ms 1484 KB Output is correct
16 Correct 681 ms 82360 KB Output is correct
17 Correct 0 ms 348 KB Output is correct
18 Correct 0 ms 348 KB Output is correct
19 Correct 0 ms 344 KB Output is correct
20 Correct 0 ms 348 KB Output is correct
21 Correct 1 ms 344 KB Output is correct
22 Correct 0 ms 348 KB Output is correct
23 Correct 1331 ms 134868 KB Output is correct
24 Correct 0 ms 348 KB Output is correct
25 Correct 4 ms 1116 KB Output is correct
26 Correct 69 ms 1868 KB Output is correct
27 Correct 95 ms 2372 KB Output is correct
28 Correct 429 ms 53652 KB Output is correct
29 Correct 706 ms 80680 KB Output is correct
30 Correct 964 ms 107712 KB Output is correct
31 Correct 1302 ms 135104 KB Output is correct
32 Correct 0 ms 344 KB Output is correct
33 Correct 0 ms 344 KB Output is correct
34 Correct 0 ms 348 KB Output is correct
35 Correct 0 ms 348 KB Output is correct
36 Correct 0 ms 348 KB Output is correct
37 Correct 0 ms 348 KB Output is correct
38 Correct 0 ms 348 KB Output is correct
39 Correct 0 ms 348 KB Output is correct
40 Correct 0 ms 348 KB Output is correct
41 Correct 0 ms 348 KB Output is correct
42 Correct 0 ms 348 KB Output is correct
43 Correct 41 ms 1348 KB Output is correct
44 Correct 67 ms 1748 KB Output is correct
45 Correct 582 ms 65564 KB Output is correct
46 Correct 914 ms 96700 KB Output is correct
47 Correct 960 ms 95700 KB Output is correct

Subtask #3
0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 344 KB Output is correct
2 Correct 0 ms 348 KB Output is correct
3 Correct 0 ms 348 KB Output is correct
4 Correct 0 ms 348 KB Output is correct
5 Correct 0 ms 348 KB Output is correct
6 Correct 0 ms 348 KB Output is correct
7 Correct 0 ms 348 KB Output is correct
8 Correct 0 ms 348 KB Output is correct
9 Correct 676 ms 81768 KB Output is correct
10 Correct 35 ms 8392 KB Output is correct
11 Correct 274 ms 44244 KB Output is correct
12 Correct 60 ms 12484 KB Output is correct
13 Correct 1576 ms 25044 KB Output is correct
14 Correct 19 ms 860 KB Output is correct
15 Correct 45 ms 1484 KB Output is correct
16 Correct 681 ms 82360 KB Output is correct
17 Correct 0 ms 348 KB Output is correct
18 Correct 0 ms 348 KB Output is correct
19 Correct 0 ms 344 KB Output is correct
20 Correct 0 ms 348 KB Output is correct
21 Correct 1 ms 344 KB Output is correct
22 Correct 0 ms 348 KB Output is correct
23 Correct 1331 ms 134868 KB Output is correct
24 Correct 0 ms 348 KB Output is correct
25 Correct 4 ms 1116 KB Output is correct
26 Correct 69 ms 1868 KB Output is correct
27 Correct 95 ms 2372 KB Output is correct
28 Correct 429 ms 53652 KB Output is correct
29 Correct 706 ms 80680 KB Output is correct
30 Correct 964 ms 107712 KB Output is correct
31 Correct 1302 ms 135104 KB Output is correct
32 Correct 0 ms 344 KB Output is correct
33 Correct 0 ms 344 KB Output is correct
34 Correct 0 ms 348 KB Output is correct
35 Correct 0 ms 348 KB Output is correct
36 Correct 0 ms 348 KB Output is correct
37 Correct 0 ms 348 KB Output is correct
38 Correct 0 ms 348 KB Output is correct
39 Correct 0 ms 348 KB Output is correct
40 Correct 0 ms 348 KB Output is correct
41 Correct 0 ms 348 KB Output is correct
42 Correct 0 ms 348 KB Output is correct
43 Correct 41 ms 1348 KB Output is correct
44 Correct 67 ms 1748 KB Output is correct
45 Correct 582 ms 65564 KB Output is correct
46 Correct 914 ms 96700 KB Output is correct
47 Correct 960 ms 95700 KB Output is correct
48 Correct 0 ms 344 KB Output is correct
49 Correct 0 ms 348 KB Output is correct
50 Correct 0 ms 348 KB Output is correct
51 Correct 0 ms 348 KB Output is correct
52 Correct 0 ms 348 KB Output is correct
53 Correct 0 ms 348 KB Output is correct
54 Correct 0 ms 348 KB Output is correct
55 Execution timed out 3605 ms 135860 KB Time limit exceeded
56 Halted 0 ms 0 KB -

Subtask #4
0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 344 KB Output is correct
2 Correct 0 ms 348 KB Output is correct
3 Correct 0 ms 348 KB Output is correct
4 Correct 0 ms 348 KB Output is correct
5 Correct 0 ms 348 KB Output is correct
6 Correct 0 ms 348 KB Output is correct
7 Correct 0 ms 348 KB Output is correct
8 Correct 0 ms 348 KB Output is correct
9 Correct 676 ms 81768 KB Output is correct
10 Correct 35 ms 8392 KB Output is correct
11 Correct 274 ms 44244 KB Output is correct
12 Correct 60 ms 12484 KB Output is correct
13 Correct 1576 ms 25044 KB Output is correct
14 Correct 19 ms 860 KB Output is correct
15 Correct 45 ms 1484 KB Output is correct
16 Correct 681 ms 82360 KB Output is correct
17 Correct 0 ms 344 KB Output is correct
18 Correct 0 ms 348 KB Output is correct
19 Correct 0 ms 348 KB Output is correct
20 Correct 1119 ms 112168 KB Output is correct
21 Correct 1342 ms 113216 KB Output is correct
22 Correct 1400 ms 112312 KB Output is correct
23 Correct 1477 ms 139444 KB Output is correct
24 Execution timed out 3564 ms 28540 KB Time limit exceeded
25 Halted 0 ms 0 KB -

Subtask #5
0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 344 KB Output is correct
2 Correct 0 ms 348 KB Output is correct
3 Correct 0 ms 348 KB Output is correct
4 Correct 0 ms 348 KB Output is correct
5 Correct 0 ms 348 KB Output is correct
6 Correct 0 ms 348 KB Output is correct
7 Correct 0 ms 348 KB Output is correct
8 Correct 0 ms 348 KB Output is correct
9 Correct 676 ms 81768 KB Output is correct
10 Correct 35 ms 8392 KB Output is correct
11 Correct 274 ms 44244 KB Output is correct
12 Correct 60 ms 12484 KB Output is correct
13 Correct 1576 ms 25044 KB Output is correct
14 Correct 19 ms 860 KB Output is correct
15 Correct 45 ms 1484 KB Output is correct
16 Correct 681 ms 82360 KB Output is correct
17 Correct 1659 ms 164536 KB Output is correct
18 Correct 1613 ms 164568 KB Output is correct
19 Correct 1368 ms 112456 KB Output is correct
20 Execution timed out 3540 ms 126904 KB Time limit exceeded
21 Halted 0 ms 0 KB -

Subtask #6
0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 344 KB Output is correct
2 Correct 0 ms 348 KB Output is correct
3 Correct 0 ms 348 KB Output is correct
4 Correct 0 ms 348 KB Output is correct
5 Correct 0 ms 348 KB Output is correct
6 Correct 0 ms 348 KB Output is correct
7 Correct 0 ms 348 KB Output is correct
8 Correct 0 ms 348 KB Output is correct
9 Correct 676 ms 81768 KB Output is correct
10 Correct 35 ms 8392 KB Output is correct
11 Correct 274 ms 44244 KB Output is correct
12 Correct 60 ms 12484 KB Output is correct
13 Correct 1576 ms 25044 KB Output is correct
14 Correct 19 ms 860 KB Output is correct
15 Correct 45 ms 1484 KB Output is correct
16 Correct 681 ms 82360 KB Output is correct
17 Correct 0 ms 348 KB Output is correct
18 Correct 0 ms 348 KB Output is correct
19 Correct 0 ms 344 KB Output is correct
20 Correct 0 ms 348 KB Output is correct
21 Correct 1 ms 344 KB Output is correct
22 Correct 0 ms 348 KB Output is correct
23 Correct 1331 ms 134868 KB Output is correct
24 Correct 0 ms 348 KB Output is correct
25 Correct 4 ms 1116 KB Output is correct
26 Correct 69 ms 1868 KB Output is correct
27 Correct 95 ms 2372 KB Output is correct
28 Correct 429 ms 53652 KB Output is correct
29 Correct 706 ms 80680 KB Output is correct
30 Correct 964 ms 107712 KB Output is correct
31 Correct 1302 ms 135104 KB Output is correct
32 Correct 0 ms 344 KB Output is correct
33 Correct 0 ms 344 KB Output is correct
34 Correct 0 ms 348 KB Output is correct
35 Correct 0 ms 348 KB Output is correct
36 Correct 0 ms 348 KB Output is correct
37 Correct 0 ms 348 KB Output is correct
38 Correct 0 ms 348 KB Output is correct
39 Correct 0 ms 348 KB Output is correct
40 Correct 0 ms 348 KB Output is correct
41 Correct 0 ms 348 KB Output is correct
42 Correct 0 ms 348 KB Output is correct
43 Correct 41 ms 1348 KB Output is correct
44 Correct 67 ms 1748 KB Output is correct
45 Correct 582 ms 65564 KB Output is correct
46 Correct 914 ms 96700 KB Output is correct
47 Correct 960 ms 95700 KB Output is correct
48 Correct 0 ms 344 KB Output is correct
49 Correct 0 ms 348 KB Output is correct
50 Correct 0 ms 348 KB Output is correct
51 Correct 0 ms 348 KB Output is correct
52 Correct 0 ms 348 KB Output is correct
53 Correct 0 ms 348 KB Output is correct
54 Correct 0 ms 348 KB Output is correct
55 Execution timed out 3605 ms 135860 KB Time limit exceeded
56 Halted 0 ms 0 KB -