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Submission #1058387

# Submission time Handle Problem Language Result Execution time Memory
1058387 2024-08-14T09:43:17 Z vjudge1 Fountain Parks (IOI21_parks) C++17
15 / 100
 3500 ms 164908 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(2);
    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;

    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:205:30: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  205 |         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 348 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 82128 KB Output is correct
10 Correct 37 ms 8404 KB Output is correct
11 Correct 264 ms 44240 KB Output is correct
12 Correct 61 ms 12444 KB Output is correct
13 Correct 1533 ms 24888 KB Output is correct
14 Correct 20 ms 860 KB Output is correct
15 Correct 45 ms 1248 KB Output is correct
16 Correct 639 ms 82192 KB Output is correct

Subtask #2
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 348 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 82128 KB Output is correct
10 Correct 37 ms 8404 KB Output is correct
11 Correct 264 ms 44240 KB Output is correct
12 Correct 61 ms 12444 KB Output is correct
13 Correct 1533 ms 24888 KB Output is correct
14 Correct 20 ms 860 KB Output is correct
15 Correct 45 ms 1248 KB Output is correct
16 Correct 639 ms 82192 KB Output is correct
17 Correct 1 ms 348 KB Output is correct
18 Correct 0 ms 348 KB Output is correct
19 Correct 0 ms 348 KB Output is correct
20 Correct 0 ms 348 KB Output is correct
21 Correct 0 ms 348 KB Output is correct
22 Correct 0 ms 348 KB Output is correct
23 Correct 1299 ms 133856 KB Output is correct
24 Correct 0 ms 348 KB Output is correct
25 Correct 3 ms 1224 KB Output is correct
26 Correct 76 ms 1872 KB Output is correct
27 Correct 99 ms 2372 KB Output is correct
28 Correct 404 ms 53924 KB Output is correct
29 Correct 673 ms 81720 KB Output is correct
30 Correct 976 ms 106940 KB Output is correct
31 Correct 1294 ms 135084 KB Output is correct
32 Correct 0 ms 348 KB Output is correct
33 Correct 1 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 1 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 440 KB Output is correct
42 Correct 1 ms 344 KB Output is correct
43 Correct 43 ms 1124 KB Output is correct
44 Correct 69 ms 1840 KB Output is correct
45 Correct 564 ms 65468 KB Output is correct
46 Correct 953 ms 96308 KB Output is correct
47 Correct 969 ms 95384 KB Output is correct

Subtask #3
0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 348 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 82128 KB Output is correct
10 Correct 37 ms 8404 KB Output is correct
11 Correct 264 ms 44240 KB Output is correct
12 Correct 61 ms 12444 KB Output is correct
13 Correct 1533 ms 24888 KB Output is correct
14 Correct 20 ms 860 KB Output is correct
15 Correct 45 ms 1248 KB Output is correct
16 Correct 639 ms 82192 KB Output is correct
17 Correct 1 ms 348 KB Output is correct
18 Correct 0 ms 348 KB Output is correct
19 Correct 0 ms 348 KB Output is correct
20 Correct 0 ms 348 KB Output is correct
21 Correct 0 ms 348 KB Output is correct
22 Correct 0 ms 348 KB Output is correct
23 Correct 1299 ms 133856 KB Output is correct
24 Correct 0 ms 348 KB Output is correct
25 Correct 3 ms 1224 KB Output is correct
26 Correct 76 ms 1872 KB Output is correct
27 Correct 99 ms 2372 KB Output is correct
28 Correct 404 ms 53924 KB Output is correct
29 Correct 673 ms 81720 KB Output is correct
30 Correct 976 ms 106940 KB Output is correct
31 Correct 1294 ms 135084 KB Output is correct
32 Correct 0 ms 348 KB Output is correct
33 Correct 1 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 1 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 440 KB Output is correct
42 Correct 1 ms 344 KB Output is correct
43 Correct 43 ms 1124 KB Output is correct
44 Correct 69 ms 1840 KB Output is correct
45 Correct 564 ms 65468 KB Output is correct
46 Correct 953 ms 96308 KB Output is correct
47 Correct 969 ms 95384 KB Output is correct
48 Correct 0 ms 348 KB Output is correct
49 Correct 0 ms 348 KB Output is correct
50 Correct 1 ms 344 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 3601 ms 135768 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 348 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 82128 KB Output is correct
10 Correct 37 ms 8404 KB Output is correct
11 Correct 264 ms 44240 KB Output is correct
12 Correct 61 ms 12444 KB Output is correct
13 Correct 1533 ms 24888 KB Output is correct
14 Correct 20 ms 860 KB Output is correct
15 Correct 45 ms 1248 KB Output is correct
16 Correct 639 ms 82192 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 348 KB Output is correct
20 Correct 1103 ms 112716 KB Output is correct
21 Correct 1312 ms 112752 KB Output is correct
22 Correct 1349 ms 111808 KB Output is correct
23 Correct 1314 ms 139444 KB Output is correct
24 Execution timed out 3548 ms 29072 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 348 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 82128 KB Output is correct
10 Correct 37 ms 8404 KB Output is correct
11 Correct 264 ms 44240 KB Output is correct
12 Correct 61 ms 12444 KB Output is correct
13 Correct 1533 ms 24888 KB Output is correct
14 Correct 20 ms 860 KB Output is correct
15 Correct 45 ms 1248 KB Output is correct
16 Correct 639 ms 82192 KB Output is correct
17 Correct 1635 ms 164908 KB Output is correct
18 Correct 1608 ms 164268 KB Output is correct
19 Correct 1392 ms 111032 KB Output is correct
20 Execution timed out 3582 ms 128040 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 348 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 82128 KB Output is correct
10 Correct 37 ms 8404 KB Output is correct
11 Correct 264 ms 44240 KB Output is correct
12 Correct 61 ms 12444 KB Output is correct
13 Correct 1533 ms 24888 KB Output is correct
14 Correct 20 ms 860 KB Output is correct
15 Correct 45 ms 1248 KB Output is correct
16 Correct 639 ms 82192 KB Output is correct
17 Correct 1 ms 348 KB Output is correct
18 Correct 0 ms 348 KB Output is correct
19 Correct 0 ms 348 KB Output is correct
20 Correct 0 ms 348 KB Output is correct
21 Correct 0 ms 348 KB Output is correct
22 Correct 0 ms 348 KB Output is correct
23 Correct 1299 ms 133856 KB Output is correct
24 Correct 0 ms 348 KB Output is correct
25 Correct 3 ms 1224 KB Output is correct
26 Correct 76 ms 1872 KB Output is correct
27 Correct 99 ms 2372 KB Output is correct
28 Correct 404 ms 53924 KB Output is correct
29 Correct 673 ms 81720 KB Output is correct
30 Correct 976 ms 106940 KB Output is correct
31 Correct 1294 ms 135084 KB Output is correct
32 Correct 0 ms 348 KB Output is correct
33 Correct 1 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 1 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 440 KB Output is correct
42 Correct 1 ms 344 KB Output is correct
43 Correct 43 ms 1124 KB Output is correct
44 Correct 69 ms 1840 KB Output is correct
45 Correct 564 ms 65468 KB Output is correct
46 Correct 953 ms 96308 KB Output is correct
47 Correct 969 ms 95384 KB Output is correct
48 Correct 0 ms 348 KB Output is correct
49 Correct 0 ms 348 KB Output is correct
50 Correct 1 ms 344 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 3601 ms 135768 KB Time limit exceeded
56 Halted 0 ms 0 KB -