oj.uz

Submission #75079

# Submission time Handle Problem Language Result Execution time Memory
75079 2018-09-08T08:53:40 Z dacin21 Highway Tolls (IOI18_highway) C++14
100 / 100
 690 ms 33320 KB 
    #include "highway.h"
     
     
     
    #include <bits/stdc++.h>
    using namespace std;
    using ll = long long;
     
    
array<int, 5> seeds = {409887653, 59456231, 56246231, 56246233, 931621953}; 
    mt19937 rng(seeds[(std::chrono::duration_cast<std::chrono::nanoseconds>(chrono::high_resolution_clock::now().time_since_epoch()).count()^179921)%seeds.size()]);
    int get_rand(int l, int r){
        return uniform_int_distribution<int>(l, r)(rng);
    }
     
    int A, B, C, M, n;
    ll initial;
    int path_len;
    int ed;
    vector<vector<pair<int, int> > > g;
    map<pair<int, int>, int> deco;
     
     
     
    vector<char> state;
    vector<int> gord;
     
    bool rec(int u, int p, int pared){
        assert(state[u] == 0);
        state[u] = 1;
        int pool = -1;
        auto add_cand = [&](int e){
            if(pool == -1){
                pool = e;
            } else {
                gord.push_back(pool);
                gord.push_back(e);
                pool = -1;
            }
        };
        for(auto const&e:g[u]){
            if(e.first == p) continue;
            if(state[e.first] == 0){
                bool did = rec(e.first, u, e.second);
                if(!did){
                    add_cand(e.second);
                }
            } else if(state[e.first] == 1){
                add_cand(e.second);
            }
        }
        state[u] = 2;
        if(pool != -1){
            gord.push_back(pool);
            gord.push_back(pared);
            return true;
        }
        return false;
    }
     
    vector<int> line_graph_allign(){
        state.assign(n, 0);
        gord.clear();
     
        rec(get_rand(0, n-1), -1, -1);
     
        if(M%2){
            assert(gord.back() == -1);
            gord.pop_back();
            gord.push_back(gord.back());
        }
     
        return gord;
    }
     
     
    int find_vertex(int M, vector<int> const&U, vector<int> const&V){
        vector<int> ord = line_graph_allign();
        for(int i=0;i<ord.size();i+=2){
            int j = 2*get_rand(0, i/2);
            swap(ord[i], ord[i-j]);
            swap(ord[i+1], ord[i-j+1]);
        }
        /*for(int i=0;i<ord.size();i+=2){
            cerr << U[ord[i]] << " " << V[i] << " | " << U[i+1] << " " << V[i+1] << "\n";
        }*/
        int l = -1, r = (M+1)/2-1;
        while(l+1 < r){
            int m = l + (r-l)/2;
     
            vector<int> v(M, 1);
            for(int i=0;i/2<=m;++i) v[ord[i]] = 0;
            ll mid = ask(v);
            if(mid == path_len*(ll)A){
                r = m;
            } else {
                l = m;
            }
        }
        map<int, int> cnt;
        for(auto const&e:{U, V}){
            for(auto const&i:{ord[2*r], ord[2*r+1]}){
                ++cnt[e[i]];
            }
        }
        for(auto const&e:cnt){
            if(e.second == 2){
                return e.first;
            }
        }
        assert(0);
        return -1;
     
    }
    int far_search(int u, vector<int> const&U, vector<int> const&V, bool fix_d){
        vector<int> ord, vis(n, 0);
        vector<int> inv_ord(n);
        vector<int> d;
        ord.push_back(u);
        d.push_back(0);
        vis[u] = 1;
        for(int i=0;i<(int)ord.size();++i){
            int v = ord[i];
            inv_ord[v] = i;
            for(auto const&f:g[v]){
                auto const e = f.first;
                if(!vis[e]){
                    vis[e] = 1;
                    ord.push_back(e);
                    d.push_back(d[i]+1);
                }
            }
        }
        assert((int)ord.size() == n);
        int l = 0, r = n;
        if(fix_d){
            l = lower_bound(d.begin(), d.end(), path_len) - d.begin();
            r = upper_bound(d.begin(), d.end(), path_len) - d.begin();
        }
        while(l+1 < r){
            int m = l + (r-l)/2;
            vector<int> v(M, 1);
            for(int i=0;i<M;++i){
                if(inv_ord[U[i]] < m && inv_ord[V[i]] < m){
                    v[i] = 0;
                }
            }
            ll dist = ask(v);
            if(dist == path_len * (ll) A){
                r = m;
            } else {
                l = m;
            }
        }
        return ord[l];
    }
     
     
    void find_pair(int N, vector<int> U, vector<int> V, int A_, int B_) {
        n=N; A=A_; B=B_;
        C = B-A;
        M = U.size();
        for(int i=0;i<M;++i){
            deco[make_pair(U[i], V[i])] = i;
            deco[make_pair(V[i], U[i])] = i;
        }
        initial = ask(vector<int>(M, 1));
        assert(initial % B == 0);
        path_len = initial / B;
        //if(path_len <= 2) ask(vector<int>(M, 1));
        g.assign(N, vector<pair<int, int> >());
        for(int i=0;i<M;++i){
            g[U[i]].emplace_back(V[i], i);
            g[V[i]].emplace_back(U[i], i);
        }
        for(auto &e:g) shuffle(e.begin(), e.end(), rng);
     
        int start = find_vertex(M, U, V);
        //cerr << "ed " << ed << " : " << U[ed] << " " << V[ed] << "\n";
        const int S = far_search(start, U, V, false);
        const int T = far_search(S, U, V, true);
        answer(S, T);
    }

Compilation message

highway.cpp: In function 'int find_vertex(int, const std::vector<int>&, const std::vector<int>&)':
highway.cpp:79:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
         for(int i=0;i<ord.size();i+=2){
                     ~^~~~~~~~~~~

Subtask #1
5.0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 248 KB Output is correct
2 Correct 2 ms 424 KB Output is correct
3 Correct 2 ms 248 KB Output is correct
4 Correct 2 ms 340 KB Output is correct
5 Correct 2 ms 376 KB Output is correct
6 Correct 2 ms 336 KB Output is correct
7 Correct 2 ms 332 KB Output is correct
8 Correct 2 ms 248 KB Output is correct
9 Correct 2 ms 420 KB Output is correct
10 Correct 3 ms 340 KB Output is correct
11 Correct 2 ms 248 KB Output is correct
12 Correct 2 ms 248 KB Output is correct

Subtask #2
7.0 / 7.0

# Verdict Execution time Memory Grader output
1 Correct 4 ms 504 KB Output is correct
2 Correct 37 ms 2632 KB Output is correct
3 Correct 372 ms 21232 KB Output is correct
4 Correct 409 ms 21244 KB Output is correct
5 Correct 391 ms 21224 KB Output is correct
6 Correct 362 ms 21232 KB Output is correct
7 Correct 385 ms 21232 KB Output is correct
8 Correct 414 ms 21236 KB Output is correct
9 Correct 372 ms 21228 KB Output is correct
10 Correct 386 ms 21224 KB Output is correct
11 Correct 385 ms 23052 KB Output is correct
12 Correct 409 ms 23604 KB Output is correct
13 Correct 410 ms 23920 KB Output is correct
14 Correct 381 ms 22388 KB Output is correct

Subtask #3
6.0 / 6.0

# Verdict Execution time Memory Grader output
1 Correct 30 ms 3256 KB Output is correct
2 Correct 49 ms 5880 KB Output is correct
3 Correct 100 ms 9712 KB Output is correct
4 Correct 303 ms 26584 KB Output is correct
5 Correct 250 ms 26568 KB Output is correct
6 Correct 254 ms 26292 KB Output is correct
7 Correct 237 ms 28628 KB Output is correct
8 Correct 243 ms 26308 KB Output is correct
9 Correct 245 ms 28332 KB Output is correct

Subtask #4
33.0 / 33.0

# Verdict Execution time Memory Grader output
1 Correct 4 ms 504 KB Output is correct
2 Correct 38 ms 2672 KB Output is correct
3 Correct 270 ms 16520 KB Output is correct
4 Correct 372 ms 21284 KB Output is correct
5 Correct 357 ms 21300 KB Output is correct
6 Correct 329 ms 21232 KB Output is correct
7 Correct 377 ms 21240 KB Output is correct
8 Correct 383 ms 21204 KB Output is correct
9 Correct 403 ms 21236 KB Output is correct
10 Correct 394 ms 21344 KB Output is correct
11 Correct 392 ms 22268 KB Output is correct
12 Correct 431 ms 22440 KB Output is correct
13 Correct 407 ms 23724 KB Output is correct
14 Correct 425 ms 23420 KB Output is correct
15 Correct 355 ms 21232 KB Output is correct
16 Correct 379 ms 21220 KB Output is correct
17 Correct 416 ms 23188 KB Output is correct
18 Correct 392 ms 22840 KB Output is correct
19 Correct 361 ms 21188 KB Output is correct
20 Correct 394 ms 24384 KB Output is correct
21 Correct 354 ms 21408 KB Output is correct
22 Correct 364 ms 21480 KB Output is correct
23 Correct 335 ms 21472 KB Output is correct
24 Correct 381 ms 22160 KB Output is correct
25 Correct 448 ms 26268 KB Output is correct

Subtask #5
18.0 / 18.0

# Verdict Execution time Memory Grader output
1 Correct 34 ms 3132 KB Output is correct
2 Correct 45 ms 3256 KB Output is correct
3 Correct 471 ms 24564 KB Output is correct
4 Correct 518 ms 27136 KB Output is correct
5 Correct 614 ms 31732 KB Output is correct
6 Correct 593 ms 31764 KB Output is correct
7 Correct 604 ms 31572 KB Output is correct
8 Correct 573 ms 31732 KB Output is correct
9 Correct 539 ms 24300 KB Output is correct
10 Correct 563 ms 24824 KB Output is correct
11 Correct 597 ms 25348 KB Output is correct
12 Correct 589 ms 30712 KB Output is correct
13 Correct 643 ms 31256 KB Output is correct
14 Correct 579 ms 33128 KB Output is correct
15 Correct 595 ms 33104 KB Output is correct
16 Correct 610 ms 28364 KB Output is correct
17 Correct 383 ms 21488 KB Output is correct
18 Correct 405 ms 21780 KB Output is correct
19 Correct 433 ms 21824 KB Output is correct
20 Correct 411 ms 21896 KB Output is correct
21 Correct 589 ms 30816 KB Output is correct

Subtask #6
31.0 / 31.0

# Verdict Execution time Memory Grader output
1 Correct 41 ms 3064 KB Output is correct
2 Correct 64 ms 3252 KB Output is correct
3 Correct 449 ms 24884 KB Output is correct
4 Correct 520 ms 25864 KB Output is correct
5 Correct 496 ms 27180 KB Output is correct
6 Correct 589 ms 31720 KB Output is correct
7 Correct 429 ms 24956 KB Output is correct
8 Correct 446 ms 25916 KB Output is correct
9 Correct 521 ms 27172 KB Output is correct
10 Correct 643 ms 31752 KB Output is correct
11 Correct 642 ms 31736 KB Output is correct
12 Correct 575 ms 31744 KB Output is correct
13 Correct 499 ms 25328 KB Output is correct
14 Correct 540 ms 24840 KB Output is correct
15 Correct 574 ms 25320 KB Output is correct
16 Correct 577 ms 24756 KB Output is correct
17 Correct 552 ms 25504 KB Output is correct
18 Correct 582 ms 24820 KB Output is correct
19 Correct 603 ms 31460 KB Output is correct
20 Correct 564 ms 32404 KB Output is correct
21 Correct 638 ms 33320 KB Output is correct
22 Correct 639 ms 33268 KB Output is correct
23 Correct 584 ms 33184 KB Output is correct
24 Correct 625 ms 33288 KB Output is correct
25 Correct 690 ms 33280 KB Output is correct
26 Correct 626 ms 33120 KB Output is correct
27 Correct 411 ms 21872 KB Output is correct
28 Correct 399 ms 21672 KB Output is correct
29 Correct 390 ms 21880 KB Output is correct
30 Correct 414 ms 21936 KB Output is correct
31 Correct 379 ms 21648 KB Output is correct
32 Correct 414 ms 21596 KB Output is correct
33 Correct 407 ms 21976 KB Output is correct
34 Correct 383 ms 21736 KB Output is correct
35 Correct 415 ms 21700 KB Output is correct
36 Correct 404 ms 21592 KB Output is correct
37 Correct 402 ms 22000 KB Output is correct
38 Correct 429 ms 22320 KB Output is correct
39 Correct 584 ms 31584 KB Output is correct
40 Correct 544 ms 30820 KB Output is correct
41 Correct 588 ms 30184 KB Output is correct
42 Correct 577 ms 30396 KB Output is correct