oj.uz

Submission #75078

# Submission time Handle Problem Language Result Execution time Memory
75078 2018-09-08T08:51:33 Z dacin21 Highway Tolls (IOI18_highway) C++14
90 / 100
 692 ms 33304 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 336 KB Output is correct
3 Correct 2 ms 248 KB Output is correct
4 Correct 2 ms 248 KB Output is correct
5 Correct 2 ms 376 KB Output is correct
6 Correct 2 ms 376 KB Output is correct
7 Correct 2 ms 248 KB Output is correct
8 Correct 2 ms 312 KB Output is correct
9 Correct 2 ms 420 KB Output is correct
10 Correct 2 ms 296 KB Output is correct
11 Correct 2 ms 336 KB Output is correct
12 Correct 2 ms 376 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 35 ms 2668 KB Output is correct
3 Correct 395 ms 21224 KB Output is correct
4 Correct 358 ms 21320 KB Output is correct
5 Correct 403 ms 21232 KB Output is correct
6 Correct 434 ms 21224 KB Output is correct
7 Correct 417 ms 21236 KB Output is correct
8 Correct 399 ms 21244 KB Output is correct
9 Correct 366 ms 21236 KB Output is correct
10 Correct 409 ms 21224 KB Output is correct
11 Correct 413 ms 22832 KB Output is correct
12 Correct 387 ms 23292 KB Output is correct
13 Correct 400 ms 22516 KB Output is correct
14 Correct 378 ms 22416 KB Output is correct

Subtask #3
6.0 / 6.0

# Verdict Execution time Memory Grader output
1 Correct 31 ms 3404 KB Output is correct
2 Correct 57 ms 6584 KB Output is correct
3 Correct 80 ms 8540 KB Output is correct
4 Correct 220 ms 28632 KB Output is correct
5 Correct 258 ms 28468 KB Output is correct
6 Correct 255 ms 26300 KB Output is correct
7 Correct 245 ms 26804 KB Output is correct
8 Correct 268 ms 28372 KB Output is correct
9 Correct 265 ms 26888 KB Output is correct

Subtask #4
33.0 / 33.0

# Verdict Execution time Memory Grader output
1 Correct 4 ms 508 KB Output is correct
2 Correct 26 ms 2632 KB Output is correct
3 Correct 306 ms 16580 KB Output is correct
4 Correct 382 ms 21312 KB Output is correct
5 Correct 366 ms 21224 KB Output is correct
6 Correct 381 ms 21220 KB Output is correct
7 Correct 350 ms 21228 KB Output is correct
8 Correct 392 ms 21208 KB Output is correct
9 Correct 427 ms 21224 KB Output is correct
10 Correct 395 ms 21244 KB Output is correct
11 Correct 418 ms 22524 KB Output is correct
12 Correct 495 ms 22584 KB Output is correct
13 Correct 420 ms 22948 KB Output is correct
14 Correct 397 ms 23364 KB Output is correct
15 Correct 370 ms 21240 KB Output is correct
16 Correct 367 ms 20872 KB Output is correct
17 Correct 393 ms 22448 KB Output is correct
18 Correct 369 ms 23428 KB Output is correct
19 Correct 381 ms 21248 KB Output is correct
20 Correct 404 ms 24132 KB Output is correct
21 Correct 398 ms 21404 KB Output is correct
22 Correct 373 ms 21424 KB Output is correct
23 Correct 353 ms 21460 KB Output is correct
24 Correct 363 ms 22168 KB Output is correct
25 Correct 417 ms 26260 KB Output is correct

Subtask #5
18.0 / 18.0

# Verdict Execution time Memory Grader output
1 Correct 41 ms 2996 KB Output is correct
2 Correct 43 ms 3188 KB Output is correct
3 Correct 452 ms 24564 KB Output is correct
4 Correct 513 ms 27204 KB Output is correct
5 Correct 622 ms 31740 KB Output is correct
6 Correct 594 ms 31756 KB Output is correct
7 Correct 622 ms 31584 KB Output is correct
8 Correct 574 ms 31720 KB Output is correct
9 Correct 506 ms 24336 KB Output is correct
10 Correct 538 ms 24828 KB Output is correct
11 Correct 565 ms 25408 KB Output is correct
12 Correct 580 ms 30820 KB Output is correct
13 Correct 611 ms 31312 KB Output is correct
14 Correct 624 ms 33136 KB Output is correct
15 Correct 593 ms 33156 KB Output is correct
16 Correct 584 ms 28352 KB Output is correct
17 Correct 444 ms 21564 KB Output is correct
18 Correct 402 ms 21736 KB Output is correct
19 Correct 409 ms 21720 KB Output is correct
20 Correct 406 ms 21808 KB Output is correct
21 Correct 606 ms 30368 KB Output is correct

Subtask #6
21.0 / 31.0

# Verdict Execution time Memory Grader output
1 Correct 41 ms 2976 KB Output is correct
2 Correct 41 ms 3260 KB Output is correct
3 Correct 452 ms 24856 KB Output is correct
4 Correct 487 ms 25908 KB Output is correct
5 Correct 504 ms 27156 KB Output is correct
6 Correct 568 ms 31688 KB Output is correct
7 Correct 431 ms 24872 KB Output is correct
8 Correct 459 ms 25908 KB Output is correct
9 Correct 510 ms 27328 KB Output is correct
10 Correct 594 ms 31788 KB Output is correct
11 Correct 610 ms 31692 KB Output is correct
12 Correct 568 ms 31720 KB Output is correct
13 Correct 563 ms 25320 KB Output is correct
14 Correct 692 ms 24824 KB Output is correct
15 Correct 572 ms 25300 KB Output is correct
16 Correct 571 ms 24788 KB Output is correct
17 Correct 604 ms 25408 KB Output is correct
18 Correct 580 ms 24724 KB Output is correct
19 Correct 552 ms 31448 KB Output is correct
20 Correct 619 ms 32320 KB Output is correct
21 Correct 608 ms 33256 KB Output is correct
22 Correct 596 ms 33248 KB Output is correct
23 Correct 542 ms 33092 KB Output is correct
24 Correct 638 ms 33304 KB Output is correct
25 Correct 604 ms 33292 KB Output is correct
26 Correct 621 ms 33200 KB Output is correct
27 Correct 398 ms 21740 KB Output is correct
28 Correct 382 ms 21688 KB Output is correct
29 Correct 418 ms 21932 KB Output is correct
30 Partially correct 394 ms 21924 KB Output is partially correct
31 Partially correct 377 ms 21664 KB Output is partially correct
32 Correct 429 ms 21600 KB Output is correct
33 Correct 388 ms 21972 KB Output is correct
34 Correct 369 ms 21844 KB Output is correct
35 Correct 413 ms 21612 KB Output is correct
36 Correct 404 ms 21596 KB Output is correct
37 Correct 418 ms 22008 KB Output is correct
38 Correct 448 ms 22304 KB Output is correct
39 Correct 583 ms 31476 KB Output is correct
40 Correct 561 ms 31268 KB Output is correct
41 Correct 593 ms 30528 KB Output is correct
42 Correct 509 ms 29976 KB Output is correct