oj.uz

Submission #642052

# Submission time Handle Problem Language Result Execution time Memory
642052 2022-09-18T10:59:22 Z piOOE Simurgh (IOI17_simurgh) C++17
70 / 100
 821 ms 5344 KB 
#include <bits/stdc++.h>
#include "simurgh.h"

using namespace std;

void my_assert(bool f) {
    if (!f) {
        cerr << "228\n";
        int x = 1337;
        while (!f) {
            x *= 2;
            cerr << "yay";
        }
    }
}

struct dsu {
    vector<int> p;

    dsu(int n = 0) {
        p.resize(n);
        iota(p.begin(), p.end(), 0);
    }

    int get(int x) {
        while (x != p[x]) x = p[x] = p[p[x]];
        return x;
    }

    bool same(int x, int y) {
        return get(x) == get(y);
    }

    bool unite(int x, int y) {
        x = get(x), y = get(y);
        if (x == y) {
            return false;
        }
        p[y] = x;
        return true;
    }
};


vector<int> find_roads(int n, std::vector<int> U, std::vector<int> V) {
    if (U.size() != n * (n - 1) / 2) {
        vector<pair<int, int>> par(n);
        vector<int> tin(n), tout(n);
        int T = 0, ans_st = 0;

        auto calc = [&](vector<int> st) {
            T = 0;
            ans_st = count_common_roads(st);
            vector<vector<pair<int, int>>> g(n);
            for (int i = 0; i < n - 1; ++i) {
                g[U[st[i]]].emplace_back(V[st[i]], i);
                g[V[st[i]]].emplace_back(U[st[i]], i);
            }
            function<void(int)> dfs = [&](int v) {
                tin[v] = T++;
                for (auto [to, i]: g[v]) {
                    if (to != par[v].first) {
                        par[to] = {v, i};
                        dfs(to);
                    }
                }
                tout[v] = T;
            };
            dfs(0);
        };

        int m = U.size();

        dsu d(n);
        vector<int> st;
        vector<bool> in_st(m);
        for (int i = 0; i < m; ++i) {
            in_st[i] = d.unite(U[i], V[i]);
            if (in_st[i]) {
                st.push_back(i);
            }
        }


        auto isp = [&](int x, int y) {
            return tin[x] <= tin[y] && tout[x] >= tout[y];
        };

        auto path = [&](int x, int y) -> vector<int> {
            int y_ = y, x_ = x;
            vector<int> ans;
            while (!isp(x, y_)) {
                ans.push_back(par[x].second);
                x = par[x].first;
            }
            while (!isp(y, x_)) {
                ans.push_back(par[y].second);
                y = par[y].first;
            }
            return ans;
        };

        calc(st);

        vector<bool> sure(m);

        for (int i = 0; i < m; ++i) {
            if (find(st.begin(), st.end(), i) == st.end()) {
                vector<int> now = path(U[i], V[i]);
                vector<int> vis;
                bool yay = false;
                for (int j: now) {
                    if (!sure[st[j]]) {
                        auto q = st;
                        q.erase(q.begin() + j);
                        q.push_back(i);
                        int val = count_common_roads(q);
                        if (val > ans_st) {
                            st = q;
                            sure[i] = true;
                            calc(st);
                            yay = true;
                            break;
                        } else if (val < ans_st) {
                            sure[st[j]] = true;
                            break;
                        } else {
                            vis.push_back(st[j]);
                        }
                    }
                }
                if (yay) {
                    for (int j: vis) {
                        sure[j] = true;
                    }
                } else {
                    if (!vis.empty()) {
                        for (int j: vis) {
                            auto it = find(st.begin(), st.end(), j);
                            if (it != st.end()) {
                                st.erase(it);
                            }
                        }
                        dsu s(n);
                        for (int j: st) {
                            assert(s.unite(U[j], V[j]));
                        }
                        for (int j = i + 1; j < m; ++j) {
                            if (s.unite(U[j], V[j])) {
                                st.push_back(j);
                            }
                        }
                        calc(st);
                    }
                }
            }
        }
        return st;
    } else {
        vector a(n, vector<int>(n, -1)), id(n, vector<int>(n));
        const int m = n * (n - 1) / 2;
        for (int i = 0; i < m; ++i) {
            id[U[i]][V[i]] = id[V[i]][U[i]] = i;
        }
        vector<int> cnt(n), left(n);
        for (int i = 0; i < n; ++i) {
            vector<int> q;
            for (int j = 0; j < n; ++j) {
                if (j != i) {
                    q.push_back(id[i][j]);
                }
            }
            cnt[i] = count_common_roads(q);
        }
        left = cnt;
        vector<int> ans;
        vector<bool> used(n);
        for (int iter = 0; iter < n; ++iter) {
            int v = -1;
            for (int i = 0; i < n; ++i) {
                if (!used[i] && (v == -1 || left[v] > left[i])) {
                    v = i;
                }
            }
            used[v] = true;
            int chosen = -1;
            if (left[v] != 0) {
                assert(left[v] == 1);
                vector<int> c;
                for (int to = 0; to < n; ++to) {
                    if (to != v && a[v][to] == -1) {
                        c.push_back(to);
                    }
                }
                while (c.size() != 1) {
                    int wait = c.size() & 1 ? c.back() : -1;
                    if (c.size() & 1) {
                        c.pop_back();
                    }
                    int sz = c.size() >> 1;
                    vector<int> st;
                    vector<bool> in_c(n);
                    for (int x: c) {
                        in_c[x] = true;
                    }
                    for (int to = 0; to < n; ++to) {
                        if (to != v && !in_c[to]) {
                            st.push_back(id[v][to]);
                        }
                    }
                    for (int i = 0; i < sz; ++i) {
                        st.push_back(id[c[i]][c[i + sz]]);
                    }
                    vector<int> L(st);
                    for (int i = 0; i < sz; ++i) {
                        L.push_back(id[v][c[i]]);
                    }
                    vector<int> R(st);
                    for (int i = sz; i < sz * 2; ++i) {
                        R.push_back(id[v][c[i]]);
                    }
                    int cntL = count_common_roads(L), cntR = count_common_roads(R);
                    if (cntL == cntR) {
                        assert(wait != -1);
                        c.clear();
                    } else if (cntL < cntR) {
                        c.erase(c.begin(), c.begin() + sz);
                    } else {
                        c.resize(sz);
                    }
                    if (wait != -1) {
                        c.push_back(wait);
                    }
                }
                assert(!c.empty());
                chosen = c[0];
                ans.push_back(id[v][chosen]);
            }
            for (int to = 0; to < n; ++to) {
                if (to != v && a[v][to] == -1) {
                    if (to != chosen) {
                        a[v][to] = a[to][v] = 0;
                    } else {
                        a[v][to] = a[to][v] = 1;
                        --left[to];
                    }
                }
            }
        }
        return ans;
    }
}

Compilation message

simurgh.cpp: In function 'std::vector<int> find_roads(int, std::vector<int>, std::vector<int>)':
simurgh.cpp:46:18: warning: comparison of integer expressions of different signedness: 'std::vector<int>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   46 |     if (U.size() != n * (n - 1) / 2) {
      |         ~~~~~~~~~^~~~~~~~~~~~~~~~~~

Subtask #1
13.0 / 13.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 212 KB correct
2 Correct 1 ms 300 KB correct
3 Correct 1 ms 212 KB correct
4 Correct 1 ms 212 KB correct
5 Correct 1 ms 212 KB correct
6 Correct 0 ms 300 KB correct
7 Correct 1 ms 300 KB correct
8 Correct 0 ms 212 KB correct
9 Correct 0 ms 300 KB correct
10 Correct 1 ms 212 KB correct
11 Correct 1 ms 212 KB correct
12 Correct 0 ms 212 KB correct
13 Correct 1 ms 212 KB correct

Subtask #2
17.0 / 17.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 212 KB correct
2 Correct 1 ms 300 KB correct
3 Correct 1 ms 212 KB correct
4 Correct 1 ms 212 KB correct
5 Correct 1 ms 212 KB correct
6 Correct 0 ms 300 KB correct
7 Correct 1 ms 300 KB correct
8 Correct 0 ms 212 KB correct
9 Correct 0 ms 300 KB correct
10 Correct 1 ms 212 KB correct
11 Correct 1 ms 212 KB correct
12 Correct 0 ms 212 KB correct
13 Correct 1 ms 212 KB correct
14 Correct 1 ms 340 KB correct
15 Correct 1 ms 340 KB correct
16 Correct 1 ms 340 KB correct
17 Correct 4 ms 212 KB correct
18 Correct 2 ms 212 KB correct
19 Correct 5 ms 328 KB correct
20 Correct 4 ms 212 KB correct
21 Correct 4 ms 212 KB correct
22 Correct 1 ms 212 KB correct
23 Correct 1 ms 300 KB correct
24 Correct 1 ms 296 KB correct
25 Correct 1 ms 212 KB correct
26 Correct 1 ms 296 KB correct
27 Correct 1 ms 212 KB correct
28 Correct 1 ms 212 KB correct
29 Correct 1 ms 212 KB correct
30 Correct 1 ms 212 KB correct
31 Correct 1 ms 212 KB correct
32 Correct 1 ms 212 KB correct
33 Correct 1 ms 300 KB correct

Subtask #3
21.0 / 21.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 212 KB correct
2 Correct 1 ms 300 KB correct
3 Correct 1 ms 212 KB correct
4 Correct 1 ms 212 KB correct
5 Correct 1 ms 212 KB correct
6 Correct 0 ms 300 KB correct
7 Correct 1 ms 300 KB correct
8 Correct 0 ms 212 KB correct
9 Correct 0 ms 300 KB correct
10 Correct 1 ms 212 KB correct
11 Correct 1 ms 212 KB correct
12 Correct 0 ms 212 KB correct
13 Correct 1 ms 212 KB correct
14 Correct 1 ms 340 KB correct
15 Correct 1 ms 340 KB correct
16 Correct 1 ms 340 KB correct
17 Correct 4 ms 212 KB correct
18 Correct 2 ms 212 KB correct
19 Correct 5 ms 328 KB correct
20 Correct 4 ms 212 KB correct
21 Correct 4 ms 212 KB correct
22 Correct 1 ms 212 KB correct
23 Correct 1 ms 300 KB correct
24 Correct 1 ms 296 KB correct
25 Correct 1 ms 212 KB correct
26 Correct 1 ms 296 KB correct
27 Correct 1 ms 212 KB correct
28 Correct 1 ms 212 KB correct
29 Correct 1 ms 212 KB correct
30 Correct 1 ms 212 KB correct
31 Correct 1 ms 212 KB correct
32 Correct 1 ms 212 KB correct
33 Correct 1 ms 300 KB correct
34 Correct 27 ms 1332 KB correct
35 Correct 673 ms 940 KB correct
36 Correct 387 ms 752 KB correct
37 Correct 16 ms 340 KB correct
38 Correct 683 ms 1088 KB correct
39 Correct 616 ms 872 KB correct
40 Correct 415 ms 744 KB correct
41 Correct 26 ms 1436 KB correct
42 Correct 821 ms 980 KB correct
43 Correct 9 ms 596 KB correct
44 Correct 8 ms 596 KB correct
45 Correct 8 ms 644 KB correct
46 Correct 7 ms 468 KB correct
47 Correct 4 ms 340 KB correct
48 Correct 1 ms 212 KB correct
49 Correct 2 ms 340 KB correct
50 Correct 4 ms 340 KB correct
51 Correct 8 ms 644 KB correct
52 Correct 9 ms 604 KB correct
53 Correct 7 ms 468 KB correct
54 Correct 9 ms 724 KB correct
55 Correct 9 ms 596 KB correct
56 Correct 9 ms 596 KB correct
57 Correct 10 ms 660 KB correct

Subtask #4
19.0 / 19.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 212 KB correct
2 Correct 0 ms 212 KB correct
3 Correct 84 ms 3388 KB correct
4 Correct 138 ms 5300 KB correct
5 Correct 142 ms 5200 KB correct
6 Correct 134 ms 5216 KB correct
7 Correct 137 ms 5196 KB correct
8 Correct 135 ms 5104 KB correct
9 Correct 138 ms 5220 KB correct
10 Correct 136 ms 5216 KB correct
11 Correct 136 ms 5104 KB correct
12 Correct 136 ms 5196 KB correct
13 Correct 0 ms 212 KB correct
14 Correct 135 ms 5216 KB correct
15 Correct 140 ms 5344 KB correct

Subtask #5
0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 212 KB correct
2 Correct 1 ms 300 KB correct
3 Correct 1 ms 212 KB correct
4 Correct 1 ms 212 KB correct
5 Correct 1 ms 212 KB correct
6 Correct 0 ms 300 KB correct
7 Correct 1 ms 300 KB correct
8 Correct 0 ms 212 KB correct
9 Correct 0 ms 300 KB correct
10 Correct 1 ms 212 KB correct
11 Correct 1 ms 212 KB correct
12 Correct 0 ms 212 KB correct
13 Correct 1 ms 212 KB correct
14 Correct 1 ms 340 KB correct
15 Correct 1 ms 340 KB correct
16 Correct 1 ms 340 KB correct
17 Correct 4 ms 212 KB correct
18 Correct 2 ms 212 KB correct
19 Correct 5 ms 328 KB correct
20 Correct 4 ms 212 KB correct
21 Correct 4 ms 212 KB correct
22 Correct 1 ms 212 KB correct
23 Correct 1 ms 300 KB correct
24 Correct 1 ms 296 KB correct
25 Correct 1 ms 212 KB correct
26 Correct 1 ms 296 KB correct
27 Correct 1 ms 212 KB correct
28 Correct 1 ms 212 KB correct
29 Correct 1 ms 212 KB correct
30 Correct 1 ms 212 KB correct
31 Correct 1 ms 212 KB correct
32 Correct 1 ms 212 KB correct
33 Correct 1 ms 300 KB correct
34 Correct 27 ms 1332 KB correct
35 Correct 673 ms 940 KB correct
36 Correct 387 ms 752 KB correct
37 Correct 16 ms 340 KB correct
38 Correct 683 ms 1088 KB correct
39 Correct 616 ms 872 KB correct
40 Correct 415 ms 744 KB correct
41 Correct 26 ms 1436 KB correct
42 Correct 821 ms 980 KB correct
43 Correct 9 ms 596 KB correct
44 Correct 8 ms 596 KB correct
45 Correct 8 ms 644 KB correct
46 Correct 7 ms 468 KB correct
47 Correct 4 ms 340 KB correct
48 Correct 1 ms 212 KB correct
49 Correct 2 ms 340 KB correct
50 Correct 4 ms 340 KB correct
51 Correct 8 ms 644 KB correct
52 Correct 9 ms 604 KB correct
53 Correct 7 ms 468 KB correct
54 Correct 9 ms 724 KB correct
55 Correct 9 ms 596 KB correct
56 Correct 9 ms 596 KB correct
57 Correct 10 ms 660 KB correct
58 Correct 1 ms 212 KB correct
59 Correct 0 ms 212 KB correct
60 Correct 84 ms 3388 KB correct
61 Correct 138 ms 5300 KB correct
62 Correct 142 ms 5200 KB correct
63 Correct 134 ms 5216 KB correct
64 Correct 137 ms 5196 KB correct
65 Correct 135 ms 5104 KB correct
66 Correct 138 ms 5220 KB correct
67 Correct 136 ms 5216 KB correct
68 Correct 136 ms 5104 KB correct
69 Correct 136 ms 5196 KB correct
70 Correct 0 ms 212 KB correct
71 Correct 135 ms 5216 KB correct
72 Correct 140 ms 5344 KB correct
73 Correct 0 ms 212 KB correct
74 Incorrect 139 ms 5212 KB WA in grader: NO
75 Halted 0 ms 0 KB -