oj.uz

Submission #379017

# Submission time Handle Problem Language Result Execution time Memory
379017 2021-03-17T08:27:36 Z jeroenodb Railway (BOI17_railway) C++14
100 / 100
 123 ms 30052 KB 
#include "bits/stdc++.h"
using namespace std;
#define all(x) begin(x),end(x)
template<typename A, typename B> ostream& operator<<(ostream &os, const pair<A, B> &p) { return os << '(' << p.first << ", " << p.second << ')'; }
template<typename T_container, typename T = typename enable_if<!is_same<T_container, string>::value, typename T_container::value_type>::type> ostream& operator<<(ostream &os, const T_container &v) { string sep; for (const T &x : v) os << sep << x, sep = " "; return os; }
#define debug(a) cerr << "(" << #a << ": " << a << ")\n";
typedef long long ll;
typedef vector<int> vi;
typedef vector<vi> vvi;
typedef pair<int,int> pi;
const int mxN = 1e5+1, oo = 1e9;

int pref[mxN], in[mxN];

struct DSU{
    vi sz,parent, highest;
    DSU(int n) {
        sz.assign(n,1);
        parent.resize(n);
        iota(all(parent),0);
        highest.resize(n);
        iota(all(highest),0);
    }
    void link(int a, int b) {
        if(sz[a]<sz[b]) {
            swap(a,b);
        }
        sz[a] = max(sz[a],sz[b]+1);
        parent[b] = a;
        if(in[highest[a]]>in[highest[b]]) {
            highest[a] = highest[b];
        }
    }
    int high(int a){
        return highest[find(a)];
    }
    void unite(int a, int b) {
        int pa = find(a),pb = find(b);
        if(pa!=pb) link(pa,pb);
    }
    int find(int a) {
        return a==parent[a]?a:parent[a] = find(parent[a]);
    }
};

vector<pi> adj[mxN];
int cnt = 0;
void dfs(int at=0, int from=-1) {
    in[at] = cnt++;
    for(auto [to,haha]: adj[at]) {
        if(to==from) continue;
        dfs(to,at);
    }
}

vi query[mxN];
void decrementlca(int a, int b) {
    query[a].push_back(b);
    query[b].push_back(a);
}

bitset<mxN> visited;
int k;
vi ans;
void lcadfs(int at, int from, DSU& dsu) {
    visited[at]=true;
    for(auto other : query[at]) {
        if(visited[other]) {
            // Offline LCA algorithm from: https://usaco.guide/CPH.pdf#page=181
            int lca = dsu.high(other);
            pref[lca]--;
        }
    }
    for(auto [to,id]: adj[at]) {
        if(to==from) continue;
        lcadfs(to,at,dsu);
        if(pref[to]>=k) {
            ans.push_back(id+1);
        }
        pref[at]+=pref[to];
    }
    dsu.unite(at,from);
}


int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    int n,m; cin >> n >> m >> k;

    for(int i=0;i<n-1;++i) {
        int a,b; cin >> a >> b;
        --a,--b;
        adj[a].push_back({b,i});
        adj[b].push_back({a,i});
    }
    dfs();

    for(int official=0;official<m;++official) {
        int s; cin >> s;
        vi nes(s);
        for(int& i: nes) {
            cin >>i; --i; 
            pref[i]++;
        }
        sort(all(nes), [&](int a, int b){return in[a]>in[b];});
        for(int i=1;i<s;++i) {
            decrementlca(nes[i-1],nes[i]);
        }
        decrementlca(nes[0],nes.back());
    }

    DSU dsu(n);
    lcadfs(0,0,dsu);
    sort(all(ans));
    cout << ans.size() << '\n';
    cout << ans << '\n';
}

Compilation message

railway.cpp: In function 'void dfs(int, int)':
railway.cpp:50:14: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
   50 |     for(auto [to,haha]: adj[at]) {
      |              ^
railway.cpp: In function 'void lcadfs(int, int, DSU&)':
railway.cpp:74:14: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
   74 |     for(auto [to,id]: adj[at]) {
      |              ^

Subtask #1
8.0 / 8.0

# Verdict Execution time Memory Grader output
1 Correct 4 ms 5100 KB Output is correct
2 Correct 8 ms 5740 KB Output is correct
3 Correct 8 ms 5740 KB Output is correct
4 Correct 4 ms 5100 KB Output is correct
5 Correct 4 ms 5100 KB Output is correct
6 Correct 9 ms 6508 KB Output is correct
7 Correct 9 ms 5868 KB Output is correct
8 Correct 7 ms 5740 KB Output is correct
9 Correct 7 ms 5740 KB Output is correct
10 Correct 4 ms 5100 KB Output is correct
11 Correct 4 ms 5100 KB Output is correct
12 Correct 4 ms 5100 KB Output is correct
13 Correct 4 ms 5100 KB Output is correct
14 Correct 4 ms 5100 KB Output is correct

Subtask #2
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 4 ms 5100 KB Output is correct
2 Correct 8 ms 5740 KB Output is correct
3 Correct 8 ms 5740 KB Output is correct
4 Correct 4 ms 5100 KB Output is correct
5 Correct 4 ms 5100 KB Output is correct
6 Correct 9 ms 6508 KB Output is correct
7 Correct 9 ms 5868 KB Output is correct
8 Correct 7 ms 5740 KB Output is correct
9 Correct 7 ms 5740 KB Output is correct
10 Correct 4 ms 5100 KB Output is correct
11 Correct 4 ms 5100 KB Output is correct
12 Correct 4 ms 5100 KB Output is correct
13 Correct 4 ms 5100 KB Output is correct
14 Correct 4 ms 5100 KB Output is correct
15 Correct 25 ms 7148 KB Output is correct
16 Correct 25 ms 7148 KB Output is correct
17 Correct 30 ms 7148 KB Output is correct
18 Correct 9 ms 6508 KB Output is correct
19 Correct 9 ms 5868 KB Output is correct
20 Correct 26 ms 7660 KB Output is correct
21 Correct 30 ms 7660 KB Output is correct
22 Correct 6 ms 5100 KB Output is correct
23 Correct 10 ms 5740 KB Output is correct
24 Correct 8 ms 5740 KB Output is correct
25 Correct 4 ms 5100 KB Output is correct
26 Correct 4 ms 5100 KB Output is correct
27 Correct 9 ms 6508 KB Output is correct
28 Correct 9 ms 5868 KB Output is correct
29 Correct 7 ms 5740 KB Output is correct
30 Correct 8 ms 5740 KB Output is correct
31 Correct 4 ms 5100 KB Output is correct
32 Correct 4 ms 5100 KB Output is correct
33 Correct 4 ms 5100 KB Output is correct
34 Correct 4 ms 5100 KB Output is correct
35 Correct 5 ms 5100 KB Output is correct

Subtask #3
7.0 / 7.0

# Verdict Execution time Memory Grader output
1 Correct 101 ms 29028 KB Output is correct
2 Correct 4 ms 5100 KB Output is correct
3 Correct 93 ms 28776 KB Output is correct
4 Correct 90 ms 28416 KB Output is correct
5 Correct 92 ms 29028 KB Output is correct
6 Correct 94 ms 30052 KB Output is correct

Subtask #4
29.0 / 29.0

# Verdict Execution time Memory Grader output
1 Correct 72 ms 20716 KB Output is correct
2 Correct 102 ms 14444 KB Output is correct
3 Correct 99 ms 13804 KB Output is correct
4 Correct 92 ms 13696 KB Output is correct
5 Correct 101 ms 13804 KB Output is correct
6 Correct 73 ms 20844 KB Output is correct
7 Correct 75 ms 20728 KB Output is correct

Subtask #5
16.0 / 16.0

# Verdict Execution time Memory Grader output
1 Correct 72 ms 20716 KB Output is correct
2 Correct 102 ms 14444 KB Output is correct
3 Correct 99 ms 13804 KB Output is correct
4 Correct 92 ms 13696 KB Output is correct
5 Correct 101 ms 13804 KB Output is correct
6 Correct 73 ms 20844 KB Output is correct
7 Correct 75 ms 20728 KB Output is correct
8 Correct 93 ms 21612 KB Output is correct
9 Correct 85 ms 21612 KB Output is correct
10 Correct 93 ms 29036 KB Output is correct
11 Correct 86 ms 29032 KB Output is correct
12 Correct 74 ms 14444 KB Output is correct
13 Correct 85 ms 14444 KB Output is correct
14 Correct 96 ms 13676 KB Output is correct
15 Correct 117 ms 13676 KB Output is correct
16 Correct 91 ms 13744 KB Output is correct
17 Correct 89 ms 13676 KB Output is correct
18 Correct 92 ms 13804 KB Output is correct
19 Correct 98 ms 14444 KB Output is correct
20 Correct 75 ms 21100 KB Output is correct
21 Correct 74 ms 21096 KB Output is correct
22 Correct 81 ms 21228 KB Output is correct

Subtask #6
25.0 / 25.0

# Verdict Execution time Memory Grader output
1 Correct 4 ms 5100 KB Output is correct
2 Correct 8 ms 5740 KB Output is correct
3 Correct 8 ms 5740 KB Output is correct
4 Correct 4 ms 5100 KB Output is correct
5 Correct 4 ms 5100 KB Output is correct
6 Correct 9 ms 6508 KB Output is correct
7 Correct 9 ms 5868 KB Output is correct
8 Correct 7 ms 5740 KB Output is correct
9 Correct 7 ms 5740 KB Output is correct
10 Correct 4 ms 5100 KB Output is correct
11 Correct 4 ms 5100 KB Output is correct
12 Correct 4 ms 5100 KB Output is correct
13 Correct 4 ms 5100 KB Output is correct
14 Correct 4 ms 5100 KB Output is correct
15 Correct 25 ms 7148 KB Output is correct
16 Correct 25 ms 7148 KB Output is correct
17 Correct 30 ms 7148 KB Output is correct
18 Correct 9 ms 6508 KB Output is correct
19 Correct 9 ms 5868 KB Output is correct
20 Correct 26 ms 7660 KB Output is correct
21 Correct 30 ms 7660 KB Output is correct
22 Correct 6 ms 5100 KB Output is correct
23 Correct 10 ms 5740 KB Output is correct
24 Correct 8 ms 5740 KB Output is correct
25 Correct 4 ms 5100 KB Output is correct
26 Correct 4 ms 5100 KB Output is correct
27 Correct 9 ms 6508 KB Output is correct
28 Correct 9 ms 5868 KB Output is correct
29 Correct 7 ms 5740 KB Output is correct
30 Correct 8 ms 5740 KB Output is correct
31 Correct 4 ms 5100 KB Output is correct
32 Correct 4 ms 5100 KB Output is correct
33 Correct 4 ms 5100 KB Output is correct
34 Correct 4 ms 5100 KB Output is correct
35 Correct 5 ms 5100 KB Output is correct
36 Correct 101 ms 29028 KB Output is correct
37 Correct 4 ms 5100 KB Output is correct
38 Correct 93 ms 28776 KB Output is correct
39 Correct 90 ms 28416 KB Output is correct
40 Correct 92 ms 29028 KB Output is correct
41 Correct 94 ms 30052 KB Output is correct
42 Correct 72 ms 20716 KB Output is correct
43 Correct 102 ms 14444 KB Output is correct
44 Correct 99 ms 13804 KB Output is correct
45 Correct 92 ms 13696 KB Output is correct
46 Correct 101 ms 13804 KB Output is correct
47 Correct 73 ms 20844 KB Output is correct
48 Correct 75 ms 20728 KB Output is correct
49 Correct 93 ms 21612 KB Output is correct
50 Correct 85 ms 21612 KB Output is correct
51 Correct 93 ms 29036 KB Output is correct
52 Correct 86 ms 29032 KB Output is correct
53 Correct 74 ms 14444 KB Output is correct
54 Correct 85 ms 14444 KB Output is correct
55 Correct 96 ms 13676 KB Output is correct
56 Correct 117 ms 13676 KB Output is correct
57 Correct 91 ms 13744 KB Output is correct
58 Correct 89 ms 13676 KB Output is correct
59 Correct 92 ms 13804 KB Output is correct
60 Correct 98 ms 14444 KB Output is correct
61 Correct 75 ms 21100 KB Output is correct
62 Correct 74 ms 21096 KB Output is correct
63 Correct 81 ms 21228 KB Output is correct
64 Correct 91 ms 21368 KB Output is correct
65 Correct 113 ms 14700 KB Output is correct
66 Correct 110 ms 14572 KB Output is correct
67 Correct 104 ms 14316 KB Output is correct
68 Correct 81 ms 13676 KB Output is correct
69 Correct 82 ms 13676 KB Output is correct
70 Correct 89 ms 21736 KB Output is correct
71 Correct 90 ms 21356 KB Output is correct
72 Correct 4 ms 5100 KB Output is correct
73 Correct 8 ms 5740 KB Output is correct
74 Correct 8 ms 5740 KB Output is correct
75 Correct 4 ms 5100 KB Output is correct
76 Correct 4 ms 5100 KB Output is correct
77 Correct 11 ms 6636 KB Output is correct
78 Correct 8 ms 5868 KB Output is correct
79 Correct 7 ms 5740 KB Output is correct
80 Correct 7 ms 5740 KB Output is correct
81 Correct 4 ms 5100 KB Output is correct
82 Correct 4 ms 5100 KB Output is correct
83 Correct 4 ms 5100 KB Output is correct
84 Correct 3 ms 5100 KB Output is correct
85 Correct 3 ms 5100 KB Output is correct
86 Correct 26 ms 7148 KB Output is correct
87 Correct 25 ms 7148 KB Output is correct
88 Correct 27 ms 7148 KB Output is correct
89 Correct 9 ms 6508 KB Output is correct
90 Correct 8 ms 5868 KB Output is correct
91 Correct 25 ms 7660 KB Output is correct
92 Correct 27 ms 7660 KB Output is correct
93 Correct 4 ms 5100 KB Output is correct
94 Correct 101 ms 29176 KB Output is correct
95 Correct 96 ms 28776 KB Output is correct
96 Correct 90 ms 28268 KB Output is correct
97 Correct 101 ms 29028 KB Output is correct
98 Correct 94 ms 29924 KB Output is correct
99 Correct 89 ms 13804 KB Output is correct
100 Correct 95 ms 13932 KB Output is correct
101 Correct 123 ms 13676 KB Output is correct
102 Correct 98 ms 14444 KB Output is correct
103 Correct 77 ms 20844 KB Output is correct
104 Correct 79 ms 21100 KB Output is correct
105 Correct 79 ms 20716 KB Output is correct
106 Correct 85 ms 21740 KB Output is correct
107 Correct 91 ms 21484 KB Output is correct
108 Correct 94 ms 29032 KB Output is correct
109 Correct 92 ms 29032 KB Output is correct
110 Correct 79 ms 14444 KB Output is correct
111 Correct 79 ms 14444 KB Output is correct
112 Correct 98 ms 13676 KB Output is correct
113 Correct 88 ms 13676 KB Output is correct