oj.uz

Submission #692672

# Submission time Handle Problem Language Result Execution time Memory
692672 2023-02-02T04:11:22 Z sharaelong Ancient Books (IOI17_books) C++17
12 / 100
 77 ms 119472 KB 
#include "books.h"
#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef pair<int, int> pii;

struct DisjointSet {
    int n;
    vector<int> parent, rank;
    DisjointSet(int _n) : n(_n) {
        parent.resize(n);
        iota(parent.begin(), parent.end(), 0);
        rank.resize(n, 0);
    }

    int find(int u) {
        return parent[u] = (u == parent[u] ? u : find(parent[u]));
    }

    void merge(int u, int v) {
        u = find(u); v = find(v);
        if (u == v) return;
        if (rank[u] > rank[v]) swap(u, v);
        parent[u] = v;
        if (rank[u] == rank[v]) ++rank[v];
    }
};

struct FenwickTree {
    vector<int> tree;
    FenwickTree(int size) {
        tree.resize(size+1, 0);
    }

    int sum(int pos) {
        int ret = 0;
        for (int i=pos+1; i>0; i &= (i-1)) ret += tree[i];
        return ret;
    }

    void add(int pos, int val) {
        for (int i=pos+1; i<tree.size(); i+=(i & -i)) tree[i] += val;
    }
};

const int MAX_N = 1e6 + 1;
const ll INF = 4e18;

DisjointSet dsu(MAX_N);
FenwickTree fen(MAX_N);
bool visited[MAX_N];
vector<int> cycle[MAX_N];
vector<int> adj[MAX_N];
ll dp[MAX_N];

void dfs(int here, int parent = -1) {
    bool merged = false;
    if (parent != -1) {
        int mn = *min_element(cycle[here].begin(), cycle[here].end());
        int mx = *max_element(cycle[here].begin(), cycle[here].end());
        if (fen.sum(mx) - fen.sum(mn) > 0) {
            dsu.merge(here, parent);
            for (int x: cycle[here]) fen.add(x, 1);
            if (cycle[here].size() > cycle[parent].size()) swap(cycle[here], cycle[parent]);
            for (int x: cycle[here]) cycle[parent].push_back(x);
            merged = true;
        }
    }
    
    if (!merged) {
        for (int x: cycle[here]) fen.add(x, 1);
    }
    for (int there: adj[here]) {
        dfs(there, here);
    }
    if (!merged) {
        for (int x: cycle[dsu.find(here)]) fen.add(x, -1);
    }
}

ll minimum_walk(vector<int> p, int s) {
    int n = p.size();
    vector<pii> range;
    ll jump_len = 0;
    for (int i=0; i<n; ++i) {
        if (!visited[i]) {
            int l = i, r = i;
            jump_len += abs(i-p[i]);
            visited[i] = true;
            int x = p[i];
            while (x != i) {
                l = min(l, x);
                r = max(r, x);
                jump_len += abs(x-p[x]);
                visited[x] = true;
                dsu.merge(x, i);
                x = p[x];
            }
            range.push_back({ l+1, i });
            range.push_back({ -r-1, i });
        }
    }
    
    sort(range.begin(), range.end(), [](const pii& a, const pii& b) {
        return abs(a.first) < abs(b.first);
    });
    vector<pii> st;
    for (auto[x, idx]: range) {
        // cout << x << ' ' << idx << endl;
        if (x >= 0) {
            st.push_back({ idx, 1 });
        } else {
            int remove_cnt = 0;
            while (dsu.find(st.back().first) != dsu.find(idx)) {
                dsu.merge(st.back().first, idx);
                remove_cnt++;
            }
            assert(!st.empty() && dsu.find(st.back().first) == dsu.find(idx));
            st.back().second += remove_cnt-1;
            if (st.back().second <= 0) st.pop_back();
        }
    }
    
    vector<pair<pii, int>> dfs_order;
    for (int i=0; i<n; ++i) cycle[dsu.find(i)].push_back(i);
    for (int i=0; i<n; ++i) {
        if (dsu.find(i) == i) {
            dfs_order.push_back({ { cycle[i][0], cycle[i].back() }, i });
        }
    }
    sort(dfs_order.begin(), dfs_order.end());
    
    st.clear();
    vector<int> roots;
    for (int i=0; i<dfs_order.size(); ++i) {
        while (!st.empty() && st.back().first < dfs_order[i].first.first) {
            st.pop_back();
        }
        if (!st.empty()) {
            adj[st.back().second].push_back(dfs_order[i].second);
            // cout << st.back().second << ' ' << dfs_order[i].second << endl;
        }
        if (st.empty()) roots.push_back(dfs_order[i].second);
        st.push_back({ dfs_order[i].first.second, dfs_order[i].second });
    }
    for (int r: roots) dfs(r);

    ll accum = s;
    // for (int i=0; i<n; ++i) {
    //     if (dsu.find(i) == i && cycle[i].size() >= 2) {
    //         ll l = INF, r = INF;
    //         for (int x: cycle[i]) {
    //             if (x <= s) l = min(l, (ll)s-x);
    //             if (x >= s) r = min(r, (ll)x-s);
    //         }
    //         cout << i << ' ' << l << ' ' << r << endl;
    //         if (l > INF/2) accum = max(accum, s+r);
    //         else dp[s-l] = s+r;
    //     }
    // }
    for (int root: roots) {
        if (cycle[dsu.find(root)].size() >= 2) {
        ll l = INF, r = INF;
        for (int x: cycle[root]) {
            if (x <= s) l = min(l, (ll)s-x);
            if (x >= s) r = min(r, (ll)x-s);
        }
        // cout << root << ' ' << l << ' ' << r << endl;
        if (l > INF/2) accum = max(accum, s+r);
        else dp[s-l] = s+r;
        }
    }
    
    ll ans = INF;
    for (int i=0; i<=s; ++i) {
        // cout << i << ' ' << accum << endl;
        ans = min(ans, accum-i);
        accum = max(accum, dp[i]);
    }
    // cout << jump_len << endl;
    return jump_len + 2 * ans;
}

Compilation message

books.cpp: In member function 'void FenwickTree::add(int, int)':
books.cpp:42:28: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   42 |         for (int i=pos+1; i<tree.size(); i+=(i & -i)) tree[i] += val;
      |                           ~^~~~~~~~~~~~
books.cpp: In function 'll minimum_walk(std::vector<int>, int)':
books.cpp:135:20: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<std::pair<int, int>, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  135 |     for (int i=0; i<dfs_order.size(); ++i) {
      |                   ~^~~~~~~~~~~~~~~~~

Subtask #1
12.0 / 12.0

# Verdict Execution time Memory Grader output
1 Correct 30 ms 58956 KB Output is correct
2 Correct 32 ms 58968 KB Output is correct
3 Correct 26 ms 58984 KB Output is correct
4 Correct 31 ms 58956 KB Output is correct
5 Correct 26 ms 58964 KB Output is correct
6 Correct 26 ms 58960 KB Output is correct
7 Correct 29 ms 59040 KB Output is correct
8 Correct 27 ms 59028 KB Output is correct
9 Correct 27 ms 58988 KB Output is correct
10 Correct 27 ms 58960 KB Output is correct
11 Correct 27 ms 58968 KB Output is correct
12 Correct 29 ms 58956 KB Output is correct
13 Correct 32 ms 59000 KB Output is correct
14 Correct 28 ms 58964 KB Output is correct
15 Correct 30 ms 59020 KB Output is correct
16 Correct 30 ms 59000 KB Output is correct
17 Correct 31 ms 58956 KB Output is correct
18 Correct 31 ms 59112 KB Output is correct

Subtask #2
0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 30 ms 58956 KB Output is correct
2 Correct 32 ms 58968 KB Output is correct
3 Correct 26 ms 58984 KB Output is correct
4 Correct 31 ms 58956 KB Output is correct
5 Correct 26 ms 58964 KB Output is correct
6 Correct 26 ms 58960 KB Output is correct
7 Correct 29 ms 59040 KB Output is correct
8 Correct 27 ms 59028 KB Output is correct
9 Correct 27 ms 58988 KB Output is correct
10 Correct 27 ms 58960 KB Output is correct
11 Correct 27 ms 58968 KB Output is correct
12 Correct 29 ms 58956 KB Output is correct
13 Correct 32 ms 59000 KB Output is correct
14 Correct 28 ms 58964 KB Output is correct
15 Correct 30 ms 59020 KB Output is correct
16 Correct 30 ms 59000 KB Output is correct
17 Correct 31 ms 58956 KB Output is correct
18 Correct 31 ms 59112 KB Output is correct
19 Correct 32 ms 59044 KB Output is correct
20 Correct 30 ms 58956 KB Output is correct
21 Runtime error 77 ms 119472 KB Execution killed with signal 11
22 Halted 0 ms 0 KB -

Subtask #3
0 / 28.0

# Verdict Execution time Memory Grader output
1 Correct 30 ms 58956 KB Output is correct
2 Correct 32 ms 58968 KB Output is correct
3 Correct 26 ms 58984 KB Output is correct
4 Correct 31 ms 58956 KB Output is correct
5 Correct 26 ms 58964 KB Output is correct
6 Correct 26 ms 58960 KB Output is correct
7 Correct 29 ms 59040 KB Output is correct
8 Correct 27 ms 59028 KB Output is correct
9 Correct 27 ms 58988 KB Output is correct
10 Correct 27 ms 58960 KB Output is correct
11 Correct 27 ms 58968 KB Output is correct
12 Correct 29 ms 58956 KB Output is correct
13 Correct 32 ms 59000 KB Output is correct
14 Correct 28 ms 58964 KB Output is correct
15 Correct 30 ms 59020 KB Output is correct
16 Correct 30 ms 59000 KB Output is correct
17 Correct 31 ms 58956 KB Output is correct
18 Correct 31 ms 59112 KB Output is correct
19 Correct 32 ms 59044 KB Output is correct
20 Correct 30 ms 58956 KB Output is correct
21 Runtime error 77 ms 119472 KB Execution killed with signal 11
22 Halted 0 ms 0 KB -

Subtask #4
0 / 20.0

# Verdict Execution time Memory Grader output
1 Incorrect 30 ms 59092 KB 3rd lines differ - on the 1st token, expected: '3304', found: '3574'
2 Halted 0 ms 0 KB -

Subtask #5
0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 30 ms 58956 KB Output is correct
2 Correct 32 ms 58968 KB Output is correct
3 Correct 26 ms 58984 KB Output is correct
4 Correct 31 ms 58956 KB Output is correct
5 Correct 26 ms 58964 KB Output is correct
6 Correct 26 ms 58960 KB Output is correct
7 Correct 29 ms 59040 KB Output is correct
8 Correct 27 ms 59028 KB Output is correct
9 Correct 27 ms 58988 KB Output is correct
10 Correct 27 ms 58960 KB Output is correct
11 Correct 27 ms 58968 KB Output is correct
12 Correct 29 ms 58956 KB Output is correct
13 Correct 32 ms 59000 KB Output is correct
14 Correct 28 ms 58964 KB Output is correct
15 Correct 30 ms 59020 KB Output is correct
16 Correct 30 ms 59000 KB Output is correct
17 Correct 31 ms 58956 KB Output is correct
18 Correct 31 ms 59112 KB Output is correct
19 Correct 32 ms 59044 KB Output is correct
20 Correct 30 ms 58956 KB Output is correct
21 Runtime error 77 ms 119472 KB Execution killed with signal 11
22 Halted 0 ms 0 KB -