oj.uz

답안 #780515

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
780515 2023-07-12T09:46:06 Z jakobrs Stranded Far From Home (BOI22_island) C++17
20 / 100
 172 ms 34124 KB 
#include <algorithm>
#include <iostream>
#include <queue>
#include <tuple>
#include <utility>
#include <vector>
#include <numeric>

using i64 = int64_t;

int main() {
    std::cin.tie(nullptr)->sync_with_stdio(false);

    i64 n, m;
    std::cin >> n >> m;

    std::vector<i64> a(n);
    for (i64 i = 0; i < n; i++) std::cin >> a[i];

    std::vector<std::vector<i64>> adj(n);
    std::vector<std::vector<i64>> children(n);
    for (i64 i = 0; i < m; i++) {
        i64 u, v;
        std::cin >> u >> v;
        u--, v--;

        adj[u].push_back(v);
        adj[v].push_back(u);

        children[std::min(u, v)].push_back(std::max(u, v));
    }

    bool s = true;
    for (i64 i = 0; i < n; i++) {
        for (i64 j : children[i]) {
            if (a[j] > a[i]) {
                s = false;
                goto bad;
            }
        }
    }
bad:;

    if (n <= 2000 && m <= 2000) {
        std::string result;
        result.reserve(n);

        std::vector<i64> visited(n);
        for (i64 i = 0; i < n; i++) {
            struct Node {
                i64 size;
                i64 idx;

                bool operator<(const Node &rhs) const {
                    return std::tie(rhs.size, idx) < std::tie(size, rhs.idx);
                }
            };

            std::priority_queue<Node> q;
            std::fill(visited.begin(), visited.end(), false);
            visited[i] = true;

            i64 mass = a[i];
            q.push(Node{.size = 0, .idx = i});

            while (!q.empty()) {
                Node node = q.top();
                if (node.size > mass) break;
                mass += node.size;

                q.pop();
                for (i64 j : adj[node.idx]) {
                    if (!visited[j]) {
                        visited[j] = true;
                        q.push(Node{.size = a[j], .idx = j});
                    }
                }
            }

            result.push_back(q.empty() ? '1' : '0');
        }

        std::cout << result;
    } else if (s) {
        std::string result(n, '0');

        std::vector<i64> sizes(n);
        for (i64 i = n - 1; i >= 0; i--) {
            sizes[i] = a[i];

            for (i64 j : children[i]) {
                sizes[i] += sizes[j];
            }
        }

        result[0] = '1';

        for (i64 i = 0; i < n; i++) {
            if (result[i] == '1') {
                for (i64 j : children[i]) {
                    if (sizes[j] >= a[i]) {
                        result[j] = '1';
                    }
                }
            }
        }

        std::cout << result;
    } else {
        struct Node {
            i64 max;
            i64 acc;
            std::vector<Node> replaces;

            Node(i64 max, i64 acc, std::vector<Node> &&replaces) : max(max), acc(acc), replaces(std::move(replaces)) {}

            // void visualise(std::string prefix) const {
            //     std::cout << prefix << "max: " << max << '\n';
            //     std::cout << prefix << "acc: " << acc << "\n";
            //     std::cout << prefix << "replaces:\n";
            //     for (const Node &node : replaces) {
            //         node.visualise(prefix + "  ");
            //     }
            // }
        };

        std::vector<Node> ltr;
        ltr.push_back({(i64)200'000 * (i64)1'000'000 + (i64)100, 0, {}});
        for (i64 x : a) {
            std::vector<Node> replaces;
            i64 acc = ltr.back().acc;
            while (x >= ltr.back().max) {
                replaces.push_back(std::move(ltr.back()));
                ltr.pop_back();
            }
            ltr.emplace_back(
                /* max */ x,
                /* acc */ acc - x,
                /* replaces */ std::move(replaces));
        }

        i64 total = std::accumulate(a.begin(), a.end(), (i64)0);

        std::string result(n, '0');

        std::vector<std::pair<i64, i64>> rtl;
        rtl.push_back({(i64)200'000 * (i64)1'000'000 + (i64)100, 0});
        for (i64 i = 0; i < n; i++) {
            i64 x = a[n - i - 1];

            // std::cout << n - i - 1 << '\n';
            // for (auto [x, y] : rtl) {
            //     std::cout << x << ' ' << y << '\n';
            // }

            std::vector<Node> replaced = std::move(ltr.back().replaces);
            ltr.pop_back();
            for (i64 i = 0; i < replaced.size(); i++) {
                ltr.push_back(std::move(replaced[replaced.size() - i - 1]));
            }

            // for (const Node &node : ltr) {
            //     node.visualise("");
            // }

            i64 mass = x;
            auto rightwards = rtl.rbegin();
            auto leftwards = ltr.rbegin();
            while (true) {
                bool either = false;
                // try going right
                auto it =
                    std::upper_bound(rtl.rbegin(), rtl.rend(), mass,
                                     [](i64 mass, std::pair<i64, i64> pair) {
                                         return mass < pair.first;
                                     });

                if (std::distance(rightwards, it) > 0) {
                    either = true;
                    mass += it->second - rightwards->second;
                    rightwards = it;
                }

                auto rit = std::upper_bound(
                    ltr.rbegin(), ltr.rend(), mass,
                    [](i64 mass, const Node &node) { return mass < node.max; });

                if (std::distance(leftwards, rit) > 0) {
                    either = true;
                    mass += rit->acc - leftwards->acc;
                    leftwards = rit;
                }

                if (!either) break;
            }

            if (mass == total) {
                result[n - i - 1] = '1';
            }

            // std::cout << "converted " << mass << " people\n";

            i64 acc = rtl.back().second;
            while (x >= rtl.back().first) {
                rtl.pop_back();
            }
            rtl.push_back({x, acc - x});
        }

        std::cout << result;
    }
}

Compilation message

island.cpp: In function 'int main()':
island.cpp:158:31: warning: comparison of integer expressions of different signedness: 'i64' {aka 'long int'} and 'std::vector<main()::Node>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  158 |             for (i64 i = 0; i < replaced.size(); i++) {
      |                             ~~^~~~~~~~~~~~~~~~~

Subtask #1
10.0 / 10.0

# 결과 실행 시간 메모리 Grader output
1 Correct 0 ms 212 KB Output is correct
2 Correct 0 ms 212 KB Output is correct
3 Correct 0 ms 212 KB Output is correct
4 Correct 150 ms 532 KB Output is correct
5 Correct 147 ms 544 KB Output is correct
6 Correct 172 ms 512 KB Output is correct
7 Correct 147 ms 524 KB Output is correct
8 Correct 103 ms 468 KB Output is correct
9 Correct 154 ms 568 KB Output is correct
10 Correct 50 ms 556 KB Output is correct
11 Correct 47 ms 468 KB Output is correct
12 Correct 49 ms 468 KB Output is correct
13 Correct 87 ms 468 KB Output is correct
14 Correct 86 ms 468 KB Output is correct

Subtask #2
10.0 / 10.0

# 결과 실행 시간 메모리 Grader output
1 Correct 0 ms 212 KB Output is correct
2 Correct 0 ms 212 KB Output is correct
3 Correct 111 ms 24692 KB Output is correct
4 Correct 101 ms 24684 KB Output is correct
5 Correct 103 ms 23856 KB Output is correct
6 Correct 108 ms 24604 KB Output is correct
7 Correct 113 ms 24552 KB Output is correct
8 Correct 110 ms 24660 KB Output is correct
9 Correct 101 ms 24868 KB Output is correct
10 Correct 59 ms 22628 KB Output is correct
11 Correct 59 ms 22596 KB Output is correct
12 Correct 111 ms 24656 KB Output is correct
13 Correct 103 ms 25724 KB Output is correct
14 Correct 101 ms 25708 KB Output is correct
15 Correct 108 ms 25700 KB Output is correct
16 Correct 64 ms 25448 KB Output is correct

Subtask #3
0 / 15.0

# 결과 실행 시간 메모리 Grader output
1 Correct 0 ms 212 KB Output is correct
2 Incorrect 139 ms 34124 KB Output isn't correct
3 Halted 0 ms 0 KB -

Subtask #4
0 / 30.0

# 결과 실행 시간 메모리 Grader output
1 Correct 0 ms 212 KB Output is correct
2 Incorrect 127 ms 32864 KB Output isn't correct
3 Halted 0 ms 0 KB -

Subtask #5
0 / 35.0

# 결과 실행 시간 메모리 Grader output
1 Correct 0 ms 212 KB Output is correct
2 Correct 0 ms 212 KB Output is correct
3 Correct 0 ms 212 KB Output is correct
4 Correct 150 ms 532 KB Output is correct
5 Correct 147 ms 544 KB Output is correct
6 Correct 172 ms 512 KB Output is correct
7 Correct 147 ms 524 KB Output is correct
8 Correct 103 ms 468 KB Output is correct
9 Correct 154 ms 568 KB Output is correct
10 Correct 50 ms 556 KB Output is correct
11 Correct 47 ms 468 KB Output is correct
12 Correct 49 ms 468 KB Output is correct
13 Correct 87 ms 468 KB Output is correct
14 Correct 86 ms 468 KB Output is correct
15 Correct 0 ms 212 KB Output is correct
16 Correct 0 ms 212 KB Output is correct
17 Correct 111 ms 24692 KB Output is correct
18 Correct 101 ms 24684 KB Output is correct
19 Correct 103 ms 23856 KB Output is correct
20 Correct 108 ms 24604 KB Output is correct
21 Correct 113 ms 24552 KB Output is correct
22 Correct 110 ms 24660 KB Output is correct
23 Correct 101 ms 24868 KB Output is correct
24 Correct 59 ms 22628 KB Output is correct
25 Correct 59 ms 22596 KB Output is correct
26 Correct 111 ms 24656 KB Output is correct
27 Correct 103 ms 25724 KB Output is correct
28 Correct 101 ms 25708 KB Output is correct
29 Correct 108 ms 25700 KB Output is correct
30 Correct 64 ms 25448 KB Output is correct
31 Correct 0 ms 212 KB Output is correct
32 Incorrect 139 ms 34124 KB Output isn't correct
33 Halted 0 ms 0 KB -