oj.uz

답안 #21582

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
21582 2017-04-14T14:13:38 Z Ushio Railway Trip (JOI17_railway_trip) C++14
20 / 100
 2000 ms 46448 KB 
#include <bits/stdc++.h>
#define SZ(x) ((int) (x).size())
using namespace std;

const int INF = 0x3f3f3f3f;

int main() {
    #ifdef LOCAL_RUN
    freopen("task.in", "r", stdin);
    freopen("task.out", "w", stdout);
    //freopen("task.err", "w", stderr);
    #endif // ONLINE_JUDGE
    ios::sync_with_stdio(false);
    cin.tie(0);

    int n, k, q;
    cin >> n >> k >> q;

    vector<int> A(n);
    vector<int> stk;
    vector<vector<int>> graph(n);
    for (int i = 0; i < n; ++i) {
        cin >> A[i];
        int prev = -1;
        while (!stk.empty() && A[i] > A[stk.back()]) {
            if (A[stk.back()] > prev) {
                graph[i].push_back(stk.back());
                graph[stk.back()].push_back(i);
            }
            prev = A[stk.back()];
            stk.pop_back();
        }
        if (!stk.empty()) {
            graph[i].push_back(stk.back());
            graph[stk.back()].push_back(i);
        }
        stk.push_back(i);
    }
    if (k <= 20 && q > 50) {
        vector<vector<int>> dists(n, vector<int>(k + 1, INF));
        vector<vector<int>> n1(n, vector<int>(k + 1, -1));
        vector<vector<int>> n2(n, vector<int>(k + 1, -1));
        for (int i = 0; i < n; ++i) {
            n1[i][A[i]] = i;
            dists[i][A[i]] = 0;
            queue<pair<int, int>> q;
            q.push(make_pair(i, 0));
            while (!q.empty()) {
                int node = q.front().first;
                int cost = q.front().second;
                q.pop();
                for (int to: graph[node]) {
                    if (A[to] > A[node] && dists[i][A[to]] >= cost + 1) {
                        dists[i][A[to]] = cost + 1;
                        q.push(make_pair(to, cost + 1));
                        if (n1[i][A[to]] == -1) {
                            n1[i][A[to]] = to;
                        } else {
                            n2[i][A[to]] = to;
                        }
                    }
                }
            }
        }
        vector<int> log2(n + 1, 0);
        for (int i = 2; i <= n; ++i) {
            log2[i] = log2[i / 2] + 1;
        }
        int clog2 = log2[n];
        vector<vector<int>> rmq(clog2 + 1, vector<int>(n));
        for (int i = 0; i < n; ++i) {
            rmq[0][i] = A[i];
        }
        for (int j = 1; j <= clog2; ++j) {
            int y = 1 << j - 1;
            for (int i = 0; i + (1 << j) <= n; ++i) {
                rmq[j][i] = max(rmq[j - 1][i], rmq[j - 1][i + y]);
            }
        }
        auto getMax = [&](int left, int right) -> int {
            if (right < left) {
                return -INF;
            }
            int d = log2[right - left + 1];
            return max(rmq[d][left], rmq[d][right - (1 << d) + 1]);
        };
        vector<int> valCnt(k + 1, 0);
        vector<int> posInVal(n);
        for (int i = 0; i < n; ++i) {
            posInVal[i] = valCnt[A[i]]++;
        }

        while (q-- > 0) {
            int from, to;
            cin >> from >> to;
            from--; to--;
            int h = max(A[from], A[to]);
            int ans = INF;
            if (from == 3 && to == 8) {
                cerr << dists[3][2] << endl;
            }
            for (int i = h; i <= k; ++i) {
                for (int x1: {n1[from][i], n2[from][i]}) {
                    for (int x2: {n1[to][i], n2[to][i]}) {
                        int p1 = min(x1, x2);
                        int p2 = max(x1, x2);
                        if (x1 != -1 && x2 != -1 &&
                                getMax(p1 + 1, p2 - 1) <= A[x1]) {
                            int cost = dists[from][i] + dists[to][i];
                            cost += posInVal[p2] - posInVal[p1] - 1;
                            ans = min(ans, cost);
                        }
                    }
                }
            }
            cout << ans << '\n';
        }
    } else {
        while (q-- > 0) {
            int s, d;
            cin >> s >> d;
            s--; d--;
            vector<int> dist(n, -1);
            dist[s] = 0;
            queue<int> q;
            q.push(s);
            while (!q.empty() && dist[d] == -1) {
                int node = q.front();
                q.pop();
                for (int to: graph[node]) {
                    if (dist[to] == -1) {
                        dist[to] = dist[node] + 1;
                        q.push(to);
                    }
                }
            }
            cout << dist[d] - 1 << '\n';
        }
    }
}

Subtask #1
5.0 / 5.0

# 결과 실행 시간 메모리 Grader output
1 Correct 0 ms 2188 KB Output is correct
2 Correct 0 ms 2188 KB Output is correct
3 Correct 0 ms 2188 KB Output is correct
4 Correct 0 ms 2188 KB Output is correct
5 Correct 0 ms 2188 KB Output is correct
6 Correct 0 ms 2188 KB Output is correct
7 Correct 0 ms 2188 KB Output is correct
8 Correct 0 ms 2188 KB Output is correct
9 Correct 0 ms 2188 KB Output is correct

Subtask #2
15.0 / 15.0

# 결과 실행 시간 메모리 Grader output
1 Correct 0 ms 2188 KB Output is correct
2 Correct 119 ms 8900 KB Output is correct
3 Correct 103 ms 8976 KB Output is correct
4 Correct 126 ms 9048 KB Output is correct
5 Correct 123 ms 9080 KB Output is correct
6 Correct 136 ms 9124 KB Output is correct
7 Correct 126 ms 9144 KB Output is correct
8 Correct 39 ms 8988 KB Output is correct
9 Correct 46 ms 8732 KB Output is correct
10 Correct 43 ms 8988 KB Output is correct
11 Correct 119 ms 8884 KB Output is correct
12 Correct 103 ms 8888 KB Output is correct
13 Correct 129 ms 8888 KB Output is correct
14 Correct 126 ms 8884 KB Output is correct
15 Correct 129 ms 8888 KB Output is correct
16 Correct 96 ms 8888 KB Output is correct
17 Correct 126 ms 9144 KB Output is correct
18 Correct 133 ms 9144 KB Output is correct
19 Correct 79 ms 9144 KB Output is correct

Subtask #3
0 / 25.0

# 결과 실행 시간 메모리 Grader output
1 Runtime error 73 ms 46448 KB Execution killed because of forbidden syscall writev (20)
2 Halted 0 ms 0 KB -

Subtask #4
0 / 55.0

# 결과 실행 시간 메모리 Grader output
1 Execution timed out 2000 ms 9144 KB Execution timed out
2 Halted 0 ms 0 KB -