Submission #756292

#	Time	Username	Problem	Language	Result	Execution time	Memory
756292		Shreyan_Paliwal	Toll (BOI17_toll)	C++17	7 / 100	160 ms	94788 KiB

toll

#include <bits/stdc++.h>
using namespace std;

const int maxn = 50000;
const int maxo = 10000;
const int maxk = 5;
const int logn = 19;
const int INF = 1e9;

int k, n, m, o;
pair<int,int> orders[maxo];
int dp[maxn][logn][maxk][maxk]; // from k*maxn+maxk1 --> k*(maxn+2^logn) + maxk2

int main() {
    // freopen("main.in", "r", stdin);

    fill(dp[0][0][0], dp[0][0][0] + maxn*logn*maxk*maxk, INF);

    cin >> k >> n >> m >> o;
    for (int i = 0; i < m; i++) {
        int a, b, t; cin >> a >> b >> t;
        dp[a / k][0][a%k][b%k] = t;
    }

    // for (int i = 0; i <= 1; i++) {
    //     for (int a = 0; a < 5; a++) {
    //         for (int b = 0; b < 5; b++) {
    //             cout << dp[i][0][a][b] << ' ';
    //         }
    //         cout << endl;
    //     }
    // }

    // set up binary lifting

    for (int i = 1; i < logn; i++) { // for each power of 2 jump
        for (int j = 0; j + (1 << i) <= (n-k+1)/k; j++) { // do all j where j+(power of 2) is still an actual section
            for (int a = 0; a < k; a++) {
                for (int b = 0; b < k; b++) {
                    for (int c = 0; c < k; c++) {
                        dp[j][i][a][c] = min(
                            dp[j][i][a][c],
                            dp[j][i-1][a][b]+
                            dp[j+(1<<(i-1))][i-1][b][c]
                        );
                    }
                }
            }
            // cout << j << ' ' << j+(1<<i) << endl;
            // for (int a = 0; a < 5; a++) {
            //     for (int b = 0; b < 5; b++) {
            //         cout << dp[j][i][a][b] << ' ';
            //     }
            //     cout << endl;
            // }
        }
    }

    int ans[k][k], ans2[k][k];
    for (int i = 0; i < o; i++) {
        int a, b; cin >> a >> b;
        int A = a/k, B = b/k;
        fill(ans[0], ans[0] + k*k, INF);
        // for (int j = 0; j < k; j++) ans[j][j] = 0;
        ans[a%k][a%k] = 0; // because we are starting at a%k, and only care about paths from it
        // a->b where a =/= b doesn't make sense since we haven't made jumps, and rest we aren't starting at it
        for (int j = logn-1; j >= 0; j--)
            if (((B-A)>>j) & 1) {
                // cout << B << ' ' << A << ' ' << j << endl;
                // make jump of size j
                fill(ans2[0], ans2[0] + k*k, INF);
                for (int c = 0; c < k; c++)
                    for (int d = 0; d < k; d++)
                        for (int e = 0; e < k; e++) {
                            // if (a%k == c && a%k == d && b%k == e) cout << A << ' ' << j << ' ' << d << ' ' << e << ' ' << ans[c][d] << ' ' << dp[A][j][d][e] << endl;
                            ans2[c][e] = min(
                                ans2[c][e], 
                                ans[c][d] + dp[A][j][d][e]
                            );
                        }
                A += (1<<j);
                for (int c = 0; c < k; c++)
                    for (int d = 0; d < k; d++)
                        ans[c][d] = ans2[c][d];
            }
        cout << (ans[a%k][b%k] == INF ? -1 : ans[a%k][b%k]) << endl;
    }

    return 0;
}

• Subtask 1: 7 / 7
• Subtask 2: 0 / 10
• Subtask 3: 0 / 8
• Subtask 4: 0 / 31
• Subtask 5: 0 / 44