Submission #979183

#	Time	Username	Problem	Language	Result	Execution time	Memory
979183		chautanphat	Toll (BOI17_toll)	C++14	49 / 100	3053 ms	25624 KiB

toll

#include <bits/stdc++.h>
 
using namespace std;
 
const int N = 5e4;
 
struct query
{
    int a, b, id, ans;
} queries[N];
int k, n, m, o, cost[N][5][5];
 
void dnc(int l, int r, int level = 0)
{
    if (l == r) return;
    int mid = (l+r)/2, L[n/k+1][k][k], R[n/k+1][k][k];
    for (int i = l; i <= r; i++)
        for (int a = 0; a < k; a++)
            for (int b = 0; b < k; b++)
                L[i][a][b] = R[i][a][b] = 1e9;
    for (int a = 0; a < k; a++)
        L[mid][a][a] = 0;
    for (int i = mid-1; i >= l; i--)
        for (int a = 0; a < k; a++)
            for (int b = 0; b < k; b++)
                for (int c = 0; c < k; c++)
                    L[i][a][c] = min(L[i][a][c], L[i+1][b][c]+cost[i][a][b]);
    for (int a = 0; a < k; a++)
        for (int b = 0; b < k; b++)
            R[mid+1][a][b] = cost[mid][a][b];
    for (int i = mid+2; i <= r; i++)
        for (int a = 0; a < k; a++)
            for (int b = 0; b < k; b++)
                for (int c = 0; c < k; c++)
                    R[i][c][a] = min(R[i][c][a], R[i-1][c][b]+cost[i-1][b][a]);
    for (int i = 0; i < o; i++)
    {
        int a = queries[i].a, b = queries[i].b;
        if (l <= a/k && a/k <= mid && mid+1 <= b/k && b/k <= r)
            for (int j = 0; j < k; j++)
                queries[i].ans = min(queries[i].ans, L[a/k][a%k][j]+R[b/k][j][b%k]);
    }
 
    dnc(l, mid, level+1);
    dnc(mid+1, r, level+1);
}
 
int main()
{    
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
    
    cin >> k >> n >> m >> o;
 
    for (int i = 0; i < n; i++)
        for (int a = 0; a < k; a++)
            for (int b = 0; b < k; b++)
                cost[i][a][b] = 1e9;
 
    for (int i = 0; i < m; i++)
    {
        int a, b, t;
        cin >> a >> b >> t;
        cost[a/k][a%k][b%k] = t;
    }
 
    for (int i = 0; i < o; i++)
        cin >> queries[i].a >> queries[i].b, queries[i].id = i, queries[i].ans = 1e9;
 
    dnc(0, n/k);
 
    for (int i = 0; i < o; i++)
        cout << (queries[i].ans == 1e9 ? -1 : queries[i].ans) << '\n';
    return 0;
}

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