oj.uz

Submission #693034

# Submission time Handle Problem Language Result Execution time Memory
693034 2023-02-02T09:33:30 Z sharaelong Ancient Books (IOI17_books) C++17
12 / 100
 37 ms 59092 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];
            }
            if (l < r) {
                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++;
                st.pop_back();
            }
            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:138:20: 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]
  138 |     for (int i=0; i<dfs_order.size(); ++i) {
      |                   ~^~~~~~~~~~~~~~~~~

Subtask #1
12.0 / 12.0

# Verdict Execution time Memory Grader output
1 Correct 29 ms 58964 KB Output is correct
2 Correct 27 ms 59024 KB Output is correct
3 Correct 28 ms 58964 KB Output is correct
4 Correct 28 ms 59012 KB Output is correct
5 Correct 30 ms 59008 KB Output is correct
6 Correct 27 ms 58964 KB Output is correct
7 Correct 28 ms 59016 KB Output is correct
8 Correct 28 ms 59028 KB Output is correct
9 Correct 28 ms 58996 KB Output is correct
10 Correct 37 ms 58904 KB Output is correct
11 Correct 28 ms 58900 KB Output is correct
12 Correct 29 ms 58984 KB Output is correct
13 Correct 31 ms 59012 KB Output is correct
14 Correct 34 ms 58960 KB Output is correct
15 Correct 30 ms 59020 KB Output is correct
16 Correct 30 ms 58964 KB Output is correct
17 Correct 34 ms 58916 KB Output is correct
18 Correct 29 ms 59004 KB Output is correct

Subtask #2
0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 29 ms 58964 KB Output is correct
2 Correct 27 ms 59024 KB Output is correct
3 Correct 28 ms 58964 KB Output is correct
4 Correct 28 ms 59012 KB Output is correct
5 Correct 30 ms 59008 KB Output is correct
6 Correct 27 ms 58964 KB Output is correct
7 Correct 28 ms 59016 KB Output is correct
8 Correct 28 ms 59028 KB Output is correct
9 Correct 28 ms 58996 KB Output is correct
10 Correct 37 ms 58904 KB Output is correct
11 Correct 28 ms 58900 KB Output is correct
12 Correct 29 ms 58984 KB Output is correct
13 Correct 31 ms 59012 KB Output is correct
14 Correct 34 ms 58960 KB Output is correct
15 Correct 30 ms 59020 KB Output is correct
16 Correct 30 ms 58964 KB Output is correct
17 Correct 34 ms 58916 KB Output is correct
18 Correct 29 ms 59004 KB Output is correct
19 Correct 30 ms 58952 KB Output is correct
20 Correct 30 ms 58936 KB Output is correct
21 Correct 34 ms 59092 KB Output is correct
22 Incorrect 29 ms 59012 KB 3rd lines differ - on the 1st token, expected: '2082', found: '2782'
23 Halted 0 ms 0 KB -

Subtask #3
0 / 28.0

# Verdict Execution time Memory Grader output
1 Correct 29 ms 58964 KB Output is correct
2 Correct 27 ms 59024 KB Output is correct
3 Correct 28 ms 58964 KB Output is correct
4 Correct 28 ms 59012 KB Output is correct
5 Correct 30 ms 59008 KB Output is correct
6 Correct 27 ms 58964 KB Output is correct
7 Correct 28 ms 59016 KB Output is correct
8 Correct 28 ms 59028 KB Output is correct
9 Correct 28 ms 58996 KB Output is correct
10 Correct 37 ms 58904 KB Output is correct
11 Correct 28 ms 58900 KB Output is correct
12 Correct 29 ms 58984 KB Output is correct
13 Correct 31 ms 59012 KB Output is correct
14 Correct 34 ms 58960 KB Output is correct
15 Correct 30 ms 59020 KB Output is correct
16 Correct 30 ms 58964 KB Output is correct
17 Correct 34 ms 58916 KB Output is correct
18 Correct 29 ms 59004 KB Output is correct
19 Correct 30 ms 58952 KB Output is correct
20 Correct 30 ms 58936 KB Output is correct
21 Correct 34 ms 59092 KB Output is correct
22 Incorrect 29 ms 59012 KB 3rd lines differ - on the 1st token, expected: '2082', found: '2782'
23 Halted 0 ms 0 KB -

Subtask #4
0 / 20.0

# Verdict Execution time Memory Grader output
1 Incorrect 29 ms 59024 KB 3rd lines differ - on the 1st token, expected: '3304', found: '3590'
2 Halted 0 ms 0 KB -

Subtask #5
0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 29 ms 58964 KB Output is correct
2 Correct 27 ms 59024 KB Output is correct
3 Correct 28 ms 58964 KB Output is correct
4 Correct 28 ms 59012 KB Output is correct
5 Correct 30 ms 59008 KB Output is correct
6 Correct 27 ms 58964 KB Output is correct
7 Correct 28 ms 59016 KB Output is correct
8 Correct 28 ms 59028 KB Output is correct
9 Correct 28 ms 58996 KB Output is correct
10 Correct 37 ms 58904 KB Output is correct
11 Correct 28 ms 58900 KB Output is correct
12 Correct 29 ms 58984 KB Output is correct
13 Correct 31 ms 59012 KB Output is correct
14 Correct 34 ms 58960 KB Output is correct
15 Correct 30 ms 59020 KB Output is correct
16 Correct 30 ms 58964 KB Output is correct
17 Correct 34 ms 58916 KB Output is correct
18 Correct 29 ms 59004 KB Output is correct
19 Correct 30 ms 58952 KB Output is correct
20 Correct 30 ms 58936 KB Output is correct
21 Correct 34 ms 59092 KB Output is correct
22 Incorrect 29 ms 59012 KB 3rd lines differ - on the 1st token, expected: '2082', found: '2782'
23 Halted 0 ms 0 KB -