oj.uz

Submission #693036

# Submission time Handle Problem Language Result Execution time Memory
693036 2023-02-02T09:44:55 Z sharaelong Ancient Books (IOI17_books) C++17
12 / 100
 35 ms 59160 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 && cycle[i].size() >= 2) {
            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, r+s);
            else dp[-l+s] = r+s;
        }
    }
    
    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 + 2ll * 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 28 ms 58908 KB Output is correct
2 Correct 29 ms 58940 KB Output is correct
3 Correct 29 ms 59036 KB Output is correct
4 Correct 29 ms 58940 KB Output is correct
5 Correct 32 ms 58956 KB Output is correct
6 Correct 30 ms 58964 KB Output is correct
7 Correct 29 ms 58952 KB Output is correct
8 Correct 30 ms 58988 KB Output is correct
9 Correct 33 ms 59020 KB Output is correct
10 Correct 33 ms 59024 KB Output is correct
11 Correct 29 ms 59024 KB Output is correct
12 Correct 33 ms 58964 KB Output is correct
13 Correct 29 ms 58940 KB Output is correct
14 Correct 31 ms 58920 KB Output is correct
15 Correct 30 ms 59020 KB Output is correct
16 Correct 30 ms 58964 KB Output is correct
17 Correct 31 ms 58964 KB Output is correct
18 Correct 30 ms 58964 KB Output is correct

Subtask #2
0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 28 ms 58908 KB Output is correct
2 Correct 29 ms 58940 KB Output is correct
3 Correct 29 ms 59036 KB Output is correct
4 Correct 29 ms 58940 KB Output is correct
5 Correct 32 ms 58956 KB Output is correct
6 Correct 30 ms 58964 KB Output is correct
7 Correct 29 ms 58952 KB Output is correct
8 Correct 30 ms 58988 KB Output is correct
9 Correct 33 ms 59020 KB Output is correct
10 Correct 33 ms 59024 KB Output is correct
11 Correct 29 ms 59024 KB Output is correct
12 Correct 33 ms 58964 KB Output is correct
13 Correct 29 ms 58940 KB Output is correct
14 Correct 31 ms 58920 KB Output is correct
15 Correct 30 ms 59020 KB Output is correct
16 Correct 30 ms 58964 KB Output is correct
17 Correct 31 ms 58964 KB Output is correct
18 Correct 30 ms 58964 KB Output is correct
19 Correct 31 ms 58964 KB Output is correct
20 Correct 32 ms 59024 KB Output is correct
21 Correct 35 ms 59160 KB Output is correct
22 Incorrect 31 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 28 ms 58908 KB Output is correct
2 Correct 29 ms 58940 KB Output is correct
3 Correct 29 ms 59036 KB Output is correct
4 Correct 29 ms 58940 KB Output is correct
5 Correct 32 ms 58956 KB Output is correct
6 Correct 30 ms 58964 KB Output is correct
7 Correct 29 ms 58952 KB Output is correct
8 Correct 30 ms 58988 KB Output is correct
9 Correct 33 ms 59020 KB Output is correct
10 Correct 33 ms 59024 KB Output is correct
11 Correct 29 ms 59024 KB Output is correct
12 Correct 33 ms 58964 KB Output is correct
13 Correct 29 ms 58940 KB Output is correct
14 Correct 31 ms 58920 KB Output is correct
15 Correct 30 ms 59020 KB Output is correct
16 Correct 30 ms 58964 KB Output is correct
17 Correct 31 ms 58964 KB Output is correct
18 Correct 30 ms 58964 KB Output is correct
19 Correct 31 ms 58964 KB Output is correct
20 Correct 32 ms 59024 KB Output is correct
21 Correct 35 ms 59160 KB Output is correct
22 Incorrect 31 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 32 ms 59016 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 28 ms 58908 KB Output is correct
2 Correct 29 ms 58940 KB Output is correct
3 Correct 29 ms 59036 KB Output is correct
4 Correct 29 ms 58940 KB Output is correct
5 Correct 32 ms 58956 KB Output is correct
6 Correct 30 ms 58964 KB Output is correct
7 Correct 29 ms 58952 KB Output is correct
8 Correct 30 ms 58988 KB Output is correct
9 Correct 33 ms 59020 KB Output is correct
10 Correct 33 ms 59024 KB Output is correct
11 Correct 29 ms 59024 KB Output is correct
12 Correct 33 ms 58964 KB Output is correct
13 Correct 29 ms 58940 KB Output is correct
14 Correct 31 ms 58920 KB Output is correct
15 Correct 30 ms 59020 KB Output is correct
16 Correct 30 ms 58964 KB Output is correct
17 Correct 31 ms 58964 KB Output is correct
18 Correct 30 ms 58964 KB Output is correct
19 Correct 31 ms 58964 KB Output is correct
20 Correct 32 ms 59024 KB Output is correct
21 Correct 35 ms 59160 KB Output is correct
22 Incorrect 31 ms 59012 KB 3rd lines differ - on the 1st token, expected: '2082', found: '2782'
23 Halted 0 ms 0 KB -