Submission #880418

#	Time	Username	Problem	Language	Result	Execution time	Memory
880418		VectorLi	Toll (BOI17_toll)	C++17	100 / 100	174 ms	78936 KiB

toll

#include <bits/stdc++.h>
#define long long long

using namespace std;

const int V = 50000, K = 16;
const int N = 5;
const int MAX = numeric_limits<int>::max();

struct Element {
    int a[N][N];
    int* operator [] (int i) {
        return a[i];
    }
    Element() {
        for (int i = 0; i < N; i++) {
            fill(a[i], a[i] + N, MAX);
            a[i][i] = 0;
        }
    }
};

Element operator + (Element &u, Element &v) {
    Element w;
    for (int i = 0; i < N; i++) {
        fill(w[i], w[i] + N, MAX);
    }
    for (int i = 0; i < N; i++) {
        for (int j = 0; j < N; j++) {
            for (int k = 0; k < N; k++) {
                if (u[i][k] < MAX && v[k][j] < MAX) {
                    w[i][j] = min(w[i][j], u[i][k] + v[k][j]);
                }
            }
        }
    }
    return w;
}

int n, m, k, q;
Element f[K][V];

void solve() {
    cin >> k >> n >> m >> q;
    for (int u = 0; u < n / k; u++) {
        for (int i = 0; i < N; i++) {
            fill(f[0][u][i], f[0][u][i] + N, MAX);
        }
    }
    for (int i = 0; i < m; i++) {
        int u, v;
        int w;
        cin >> u >> v >> w;
        f[0][u / k][u % k][v % k] = w;
    }

    for (int i = 0; i < K - 1; i++) {
       for (int u = 0; u < n / k; u++) {
            if (u + (1 << i) >= n / k) {
                f[i + 1][u] = f[i][u];
            } else {
                f[i + 1][u] = f[i][u] + f[i][u + (1 << i)];
            }
        }
    }

    for (int i = 0; i < q; i++) {
        int u, v;
        cin >> u >> v;
        int p = u / k;
        Element x;
        for (int j = K - 1; j >= 0; j--) {
            if (p + (1 << j) <= v / k) {
                x = x + f[j][p];
                p = p + (1 << j);
            }
        }
        if (x[u % k][v % k] < MAX) {
            cout << x[u % k][v % k] << "\n";
        } else {
            cout << -1 << "\n";
        }
    }
}

int main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    solve();
    return 0;
}

• Subtask 1: 7 / 7
• Subtask 2: 10 / 10
• Subtask 3: 8 / 8
• Subtask 4: 31 / 31
• Subtask 5: 44 / 44