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답안 #1058354

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
1058354 2024-08-14T09:32:21 Z vjudge1 분수 공원 (IOI21_parks) C++17
15 / 100
 1087 ms 162060 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 construct_roads(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);
        else add_edge(u, v);
    }

    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;
}

Compilation message

parks.cpp: In function 'int construct_roads(vi, vi)':
parks.cpp:139:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  139 |     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:203:30: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  203 |         assert(id >= 0 && id < B.size());
      |                           ~~~^~~~~~~~~~

Subtask #1
5.0 / 5.0

# 결과 실행 시간 메모리 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 344 KB Output is correct
7 Correct 0 ms 348 KB Output is correct
8 Correct 0 ms 348 KB Output is correct
9 Correct 409 ms 80616 KB Output is correct
10 Correct 25 ms 8388 KB Output is correct
11 Correct 160 ms 43580 KB Output is correct
12 Correct 36 ms 12236 KB Output is correct
13 Correct 112 ms 23076 KB Output is correct
14 Correct 3 ms 860 KB Output is correct
15 Correct 4 ms 1372 KB Output is correct
16 Correct 400 ms 80620 KB Output is correct

Subtask #2
10.0 / 10.0

# 결과 실행 시간 메모리 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 344 KB Output is correct
7 Correct 0 ms 348 KB Output is correct
8 Correct 0 ms 348 KB Output is correct
9 Correct 409 ms 80616 KB Output is correct
10 Correct 25 ms 8388 KB Output is correct
11 Correct 160 ms 43580 KB Output is correct
12 Correct 36 ms 12236 KB Output is correct
13 Correct 112 ms 23076 KB Output is correct
14 Correct 3 ms 860 KB Output is correct
15 Correct 4 ms 1372 KB Output is correct
16 Correct 400 ms 80620 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 1 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 938 ms 132188 KB Output is correct
24 Correct 0 ms 348 KB Output is correct
25 Correct 2 ms 1116 KB Output is correct
26 Correct 6 ms 1756 KB Output is correct
27 Correct 8 ms 2092 KB Output is correct
28 Correct 338 ms 52760 KB Output is correct
29 Correct 542 ms 79740 KB Output is correct
30 Correct 753 ms 105220 KB Output is correct
31 Correct 975 ms 132084 KB Output is correct
32 Correct 0 ms 348 KB Output is correct
33 Correct 0 ms 348 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 420 KB Output is correct
41 Correct 0 ms 348 KB Output is correct
42 Correct 0 ms 348 KB Output is correct
43 Correct 4 ms 1116 KB Output is correct
44 Correct 6 ms 1740 KB Output is correct
45 Correct 430 ms 64980 KB Output is correct
46 Correct 648 ms 94816 KB Output is correct
47 Correct 716 ms 93708 KB Output is correct

Subtask #3
0 / 15.0

# 결과 실행 시간 메모리 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 344 KB Output is correct
7 Correct 0 ms 348 KB Output is correct
8 Correct 0 ms 348 KB Output is correct
9 Correct 409 ms 80616 KB Output is correct
10 Correct 25 ms 8388 KB Output is correct
11 Correct 160 ms 43580 KB Output is correct
12 Correct 36 ms 12236 KB Output is correct
13 Correct 112 ms 23076 KB Output is correct
14 Correct 3 ms 860 KB Output is correct
15 Correct 4 ms 1372 KB Output is correct
16 Correct 400 ms 80620 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 1 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 938 ms 132188 KB Output is correct
24 Correct 0 ms 348 KB Output is correct
25 Correct 2 ms 1116 KB Output is correct
26 Correct 6 ms 1756 KB Output is correct
27 Correct 8 ms 2092 KB Output is correct
28 Correct 338 ms 52760 KB Output is correct
29 Correct 542 ms 79740 KB Output is correct
30 Correct 753 ms 105220 KB Output is correct
31 Correct 975 ms 132084 KB Output is correct
32 Correct 0 ms 348 KB Output is correct
33 Correct 0 ms 348 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 420 KB Output is correct
41 Correct 0 ms 348 KB Output is correct
42 Correct 0 ms 348 KB Output is correct
43 Correct 4 ms 1116 KB Output is correct
44 Correct 6 ms 1740 KB Output is correct
45 Correct 430 ms 64980 KB Output is correct
46 Correct 648 ms 94816 KB Output is correct
47 Correct 716 ms 93708 KB Output is correct
48 Correct 0 ms 348 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 Incorrect 1018 ms 127368 KB Solution announced impossible, but it is possible.
56 Halted 0 ms 0 KB -

Subtask #4
0 / 20.0

# 결과 실행 시간 메모리 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 344 KB Output is correct
7 Correct 0 ms 348 KB Output is correct
8 Correct 0 ms 348 KB Output is correct
9 Correct 409 ms 80616 KB Output is correct
10 Correct 25 ms 8388 KB Output is correct
11 Correct 160 ms 43580 KB Output is correct
12 Correct 36 ms 12236 KB Output is correct
13 Correct 112 ms 23076 KB Output is correct
14 Correct 3 ms 860 KB Output is correct
15 Correct 4 ms 1372 KB Output is correct
16 Correct 400 ms 80620 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 Incorrect 688 ms 78628 KB Solution announced impossible, but it is possible.
21 Halted 0 ms 0 KB -

Subtask #5
0 / 20.0

# 결과 실행 시간 메모리 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 344 KB Output is correct
7 Correct 0 ms 348 KB Output is correct
8 Correct 0 ms 348 KB Output is correct
9 Correct 409 ms 80616 KB Output is correct
10 Correct 25 ms 8388 KB Output is correct
11 Correct 160 ms 43580 KB Output is correct
12 Correct 36 ms 12236 KB Output is correct
13 Correct 112 ms 23076 KB Output is correct
14 Correct 3 ms 860 KB Output is correct
15 Correct 4 ms 1372 KB Output is correct
16 Correct 400 ms 80620 KB Output is correct
17 Correct 1087 ms 162060 KB Output is correct
18 Correct 1064 ms 161468 KB Output is correct
19 Incorrect 762 ms 80568 KB Solution announced impossible, but it is possible.
20 Halted 0 ms 0 KB -

Subtask #6
0 / 30.0

# 결과 실행 시간 메모리 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 344 KB Output is correct
7 Correct 0 ms 348 KB Output is correct
8 Correct 0 ms 348 KB Output is correct
9 Correct 409 ms 80616 KB Output is correct
10 Correct 25 ms 8388 KB Output is correct
11 Correct 160 ms 43580 KB Output is correct
12 Correct 36 ms 12236 KB Output is correct
13 Correct 112 ms 23076 KB Output is correct
14 Correct 3 ms 860 KB Output is correct
15 Correct 4 ms 1372 KB Output is correct
16 Correct 400 ms 80620 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 1 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 938 ms 132188 KB Output is correct
24 Correct 0 ms 348 KB Output is correct
25 Correct 2 ms 1116 KB Output is correct
26 Correct 6 ms 1756 KB Output is correct
27 Correct 8 ms 2092 KB Output is correct
28 Correct 338 ms 52760 KB Output is correct
29 Correct 542 ms 79740 KB Output is correct
30 Correct 753 ms 105220 KB Output is correct
31 Correct 975 ms 132084 KB Output is correct
32 Correct 0 ms 348 KB Output is correct
33 Correct 0 ms 348 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 420 KB Output is correct
41 Correct 0 ms 348 KB Output is correct
42 Correct 0 ms 348 KB Output is correct
43 Correct 4 ms 1116 KB Output is correct
44 Correct 6 ms 1740 KB Output is correct
45 Correct 430 ms 64980 KB Output is correct
46 Correct 648 ms 94816 KB Output is correct
47 Correct 716 ms 93708 KB Output is correct
48 Correct 0 ms 348 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 Incorrect 1018 ms 127368 KB Solution announced impossible, but it is possible.
56 Halted 0 ms 0 KB -