Submission #693202

# Submission time Handle Problem Language Result Execution time Memory
693202 2023-02-02T13:05:11 Z sharaelong Ancient Books (IOI17_books) C++17
12 / 100
36 ms 59072 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];

void dfs(int here, int parent = -1) {
    // cout << here << ' ' << parent << ": ";
    // for (int x:cycle[here]) cout << x << ' ';
    // cout << endl;
    bool merged = false;
    if (parent != -1) {
        parent = dsu.find(parent);
        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]) assert(fen.sum(x)-fen.sum(x-1) == 0);
        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);
        for (int x: cycle[dsu.find(here)]) assert(fen.sum(x)-fen.sum(x-1)==0);
    }
}

ll minimum_walk(vector<int> p, int s) {
    int n = p.size();
    vector<pair<pii, int>> 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, r }, i });
        }
    }
    
    sort(range.begin(), range.end());
    // set<pii> intv_set;
    // for (int i=0; i<range.size(); ++i) {
    //     auto[l, r] = range[i].first;
    //     auto it = intv_set.lower_bound({l, 0});
    //     while (it != intv_set.end() && (*it).first < r) {
    //         dsu.merge(range[i].second, (*it).second);
    //         it = next(it);
    //     }
    //     intv_set.insert({ r, range[i].second });
    // }
    for (int i=0; i<range.size(); ++i) {
        for (int j=i+1; j<range.size(); ++j) {
            auto[l1, r1] = range[i].first;
            auto[l2, r2] = range[j].first;
            if (r1 < r2) dsu.merge(range[i].second, range[j].second);
        }
    }
    
    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());
    
    vector<pii> st;
    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);
        else 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 ans = 0;
    for (int i=0; i<roots.size(); ++i) {
        int r = dsu.find(roots[i]);
        sort(cycle[r].begin(), cycle[r].end());
        // for (int x: cycle[r]) cout << x << ' ';
        // cout << endl;
        if (i > 0) ans += cycle[r][0];
        if (i+1 < roots.size()) ans -= cycle[r].back();
        
        if (cycle[r][0] <= s && s <= cycle[r].back()) {
            ll tmp = INF;
            for (int x: cycle[r]) tmp = min(tmp, (ll)abs(x-s));
            ans += tmp;
        }
    }
    if (!roots.empty()) {
        if (s < cycle[dsu.find(roots[0])][0]) ans += cycle[dsu.find(roots[0])][0]-s;
        if (s > cycle[dsu.find(roots.back())].back()) ans += s-cycle[dsu.find(roots.back())].back();
    }
    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:119:20: 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]
  119 |     for (int i=0; i<range.size(); ++i) {
      |                   ~^~~~~~~~~~~~~
books.cpp:120:26: 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]
  120 |         for (int j=i+1; j<range.size(); ++j) {
      |                         ~^~~~~~~~~~~~~
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) {
      |                   ~^~~~~~~~~~~~~~~~~
books.cpp:147:20: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  147 |     for (int i=0; i<roots.size(); ++i) {
      |                   ~^~~~~~~~~~~~~
books.cpp:153:17: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  153 |         if (i+1 < roots.size()) ans -= cycle[r].back();
      |             ~~~~^~~~~~~~~~~~~~
# Verdict Execution time Memory Grader output
1 Correct 28 ms 58996 KB Output is correct
2 Correct 28 ms 58964 KB Output is correct
3 Correct 28 ms 58948 KB Output is correct
4 Correct 34 ms 58908 KB Output is correct
5 Correct 29 ms 58964 KB Output is correct
6 Correct 35 ms 58976 KB Output is correct
7 Correct 35 ms 58932 KB Output is correct
8 Correct 30 ms 59000 KB Output is correct
9 Correct 34 ms 59004 KB Output is correct
10 Correct 29 ms 59012 KB Output is correct
11 Correct 32 ms 58920 KB Output is correct
12 Correct 29 ms 58964 KB Output is correct
13 Correct 32 ms 58972 KB Output is correct
14 Correct 30 ms 58984 KB Output is correct
15 Correct 34 ms 58960 KB Output is correct
16 Correct 29 ms 58952 KB Output is correct
17 Correct 29 ms 58912 KB Output is correct
18 Correct 29 ms 59032 KB Output is correct
# Verdict Execution time Memory Grader output
1 Correct 28 ms 58996 KB Output is correct
2 Correct 28 ms 58964 KB Output is correct
3 Correct 28 ms 58948 KB Output is correct
4 Correct 34 ms 58908 KB Output is correct
5 Correct 29 ms 58964 KB Output is correct
6 Correct 35 ms 58976 KB Output is correct
7 Correct 35 ms 58932 KB Output is correct
8 Correct 30 ms 59000 KB Output is correct
9 Correct 34 ms 59004 KB Output is correct
10 Correct 29 ms 59012 KB Output is correct
11 Correct 32 ms 58920 KB Output is correct
12 Correct 29 ms 58964 KB Output is correct
13 Correct 32 ms 58972 KB Output is correct
14 Correct 30 ms 58984 KB Output is correct
15 Correct 34 ms 58960 KB Output is correct
16 Correct 29 ms 58952 KB Output is correct
17 Correct 29 ms 58912 KB Output is correct
18 Correct 29 ms 59032 KB Output is correct
19 Correct 29 ms 58956 KB Output is correct
20 Correct 30 ms 59052 KB Output is correct
21 Correct 31 ms 59072 KB Output is correct
22 Incorrect 30 ms 58928 KB 3rd lines differ - on the 1st token, expected: '2082', found: '788'
23 Halted 0 ms 0 KB -
# Verdict Execution time Memory Grader output
1 Correct 28 ms 58996 KB Output is correct
2 Correct 28 ms 58964 KB Output is correct
3 Correct 28 ms 58948 KB Output is correct
4 Correct 34 ms 58908 KB Output is correct
5 Correct 29 ms 58964 KB Output is correct
6 Correct 35 ms 58976 KB Output is correct
7 Correct 35 ms 58932 KB Output is correct
8 Correct 30 ms 59000 KB Output is correct
9 Correct 34 ms 59004 KB Output is correct
10 Correct 29 ms 59012 KB Output is correct
11 Correct 32 ms 58920 KB Output is correct
12 Correct 29 ms 58964 KB Output is correct
13 Correct 32 ms 58972 KB Output is correct
14 Correct 30 ms 58984 KB Output is correct
15 Correct 34 ms 58960 KB Output is correct
16 Correct 29 ms 58952 KB Output is correct
17 Correct 29 ms 58912 KB Output is correct
18 Correct 29 ms 59032 KB Output is correct
19 Correct 29 ms 58956 KB Output is correct
20 Correct 30 ms 59052 KB Output is correct
21 Correct 31 ms 59072 KB Output is correct
22 Incorrect 30 ms 58928 KB 3rd lines differ - on the 1st token, expected: '2082', found: '788'
23 Halted 0 ms 0 KB -
# Verdict Execution time Memory Grader output
1 Incorrect 36 ms 58980 KB 3rd lines differ - on the 1st token, expected: '3304', found: '3590'
2 Halted 0 ms 0 KB -
# Verdict Execution time Memory Grader output
1 Correct 28 ms 58996 KB Output is correct
2 Correct 28 ms 58964 KB Output is correct
3 Correct 28 ms 58948 KB Output is correct
4 Correct 34 ms 58908 KB Output is correct
5 Correct 29 ms 58964 KB Output is correct
6 Correct 35 ms 58976 KB Output is correct
7 Correct 35 ms 58932 KB Output is correct
8 Correct 30 ms 59000 KB Output is correct
9 Correct 34 ms 59004 KB Output is correct
10 Correct 29 ms 59012 KB Output is correct
11 Correct 32 ms 58920 KB Output is correct
12 Correct 29 ms 58964 KB Output is correct
13 Correct 32 ms 58972 KB Output is correct
14 Correct 30 ms 58984 KB Output is correct
15 Correct 34 ms 58960 KB Output is correct
16 Correct 29 ms 58952 KB Output is correct
17 Correct 29 ms 58912 KB Output is correct
18 Correct 29 ms 59032 KB Output is correct
19 Correct 29 ms 58956 KB Output is correct
20 Correct 30 ms 59052 KB Output is correct
21 Correct 31 ms 59072 KB Output is correct
22 Incorrect 30 ms 58928 KB 3rd lines differ - on the 1st token, expected: '2082', found: '788'
23 Halted 0 ms 0 KB -