oj.uz

Submission #780533

# Submission time Handle Problem Language Result Execution time Memory
780533 2023-07-12T09:57:09 Z jakobrs Stranded Far From Home (BOI22_island) C++17
35 / 100
 176 ms 41928 KB 
#include <algorithm>
#include <iostream>
#include <numeric>
#include <queue>
#include <tuple>
#include <utility>
#include <vector>

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)) {}
        };

        static const i64 HUGE_NUMBER = (i64)200'000 * (i64)1'000'000'000 * (i64)100;

        std::vector<Node> ltr;
        ltr.push_back({HUGE_NUMBER, 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({HUGE_NUMBER, 0});
        for (i64 i = 0; i < n; i++) {
            i64 x = a[n - i - 1];

            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]));
            }

            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';
            }

            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:147:31: 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]
  147 |             for (i64 i = 0; i < replaced.size(); i++) {
      |                             ~~^~~~~~~~~~~~~~~~~

Subtask #1
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 1 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 163 ms 536 KB Output is correct
5 Correct 147 ms 468 KB Output is correct
6 Correct 176 ms 512 KB Output is correct
7 Correct 158 ms 528 KB Output is correct
8 Correct 104 ms 496 KB Output is correct
9 Correct 156 ms 568 KB Output is correct
10 Correct 49 ms 556 KB Output is correct
11 Correct 47 ms 468 KB Output is correct
12 Correct 50 ms 468 KB Output is correct
13 Correct 86 ms 468 KB Output is correct
14 Correct 93 ms 548 KB Output is correct

Subtask #2
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 212 KB Output is correct
2 Correct 0 ms 212 KB Output is correct
3 Correct 136 ms 24792 KB Output is correct
4 Correct 124 ms 24780 KB Output is correct
5 Correct 105 ms 23876 KB Output is correct
6 Correct 109 ms 24528 KB Output is correct
7 Correct 145 ms 24572 KB Output is correct
8 Correct 137 ms 24652 KB Output is correct
9 Correct 126 ms 24828 KB Output is correct
10 Correct 59 ms 22584 KB Output is correct
11 Correct 62 ms 22580 KB Output is correct
12 Correct 120 ms 24640 KB Output is correct
13 Correct 105 ms 25676 KB Output is correct
14 Correct 124 ms 25744 KB Output is correct
15 Correct 110 ms 25700 KB Output is correct
16 Correct 65 ms 25392 KB Output is correct

Subtask #3
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 212 KB Output is correct
2 Correct 127 ms 34008 KB Output is correct
3 Correct 133 ms 38728 KB Output is correct
4 Correct 114 ms 30152 KB Output is correct
5 Correct 115 ms 36476 KB Output is correct
6 Correct 136 ms 38728 KB Output is correct
7 Correct 154 ms 41888 KB Output is correct
8 Correct 158 ms 41928 KB Output is correct
9 Correct 65 ms 29220 KB Output is correct
10 Correct 131 ms 37332 KB Output is correct
11 Correct 118 ms 37028 KB Output is correct

Subtask #4
0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 212 KB Output is correct
2 Incorrect 157 ms 32880 KB Output isn't correct
3 Halted 0 ms 0 KB -

Subtask #5
0 / 35.0

# Verdict Execution time Memory Grader output
1 Correct 1 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 163 ms 536 KB Output is correct
5 Correct 147 ms 468 KB Output is correct
6 Correct 176 ms 512 KB Output is correct
7 Correct 158 ms 528 KB Output is correct
8 Correct 104 ms 496 KB Output is correct
9 Correct 156 ms 568 KB Output is correct
10 Correct 49 ms 556 KB Output is correct
11 Correct 47 ms 468 KB Output is correct
12 Correct 50 ms 468 KB Output is correct
13 Correct 86 ms 468 KB Output is correct
14 Correct 93 ms 548 KB Output is correct
15 Correct 0 ms 212 KB Output is correct
16 Correct 0 ms 212 KB Output is correct
17 Correct 136 ms 24792 KB Output is correct
18 Correct 124 ms 24780 KB Output is correct
19 Correct 105 ms 23876 KB Output is correct
20 Correct 109 ms 24528 KB Output is correct
21 Correct 145 ms 24572 KB Output is correct
22 Correct 137 ms 24652 KB Output is correct
23 Correct 126 ms 24828 KB Output is correct
24 Correct 59 ms 22584 KB Output is correct
25 Correct 62 ms 22580 KB Output is correct
26 Correct 120 ms 24640 KB Output is correct
27 Correct 105 ms 25676 KB Output is correct
28 Correct 124 ms 25744 KB Output is correct
29 Correct 110 ms 25700 KB Output is correct
30 Correct 65 ms 25392 KB Output is correct
31 Correct 1 ms 212 KB Output is correct
32 Correct 127 ms 34008 KB Output is correct
33 Correct 133 ms 38728 KB Output is correct
34 Correct 114 ms 30152 KB Output is correct
35 Correct 115 ms 36476 KB Output is correct
36 Correct 136 ms 38728 KB Output is correct
37 Correct 154 ms 41888 KB Output is correct
38 Correct 158 ms 41928 KB Output is correct
39 Correct 65 ms 29220 KB Output is correct
40 Correct 131 ms 37332 KB Output is correct
41 Correct 118 ms 37028 KB Output is correct
42 Correct 0 ms 212 KB Output is correct
43 Incorrect 157 ms 32880 KB Output isn't correct
44 Halted 0 ms 0 KB -