oj.uz

답안 #986012

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
986012 2024-05-19T15:53:08 Z tfgs Toll (BOI17_toll) C++17
100 / 100
 84 ms 19024 KB 
// spent some time confused b/c i thought that queries had to be between
// different blocks. but this is only edges, queries in the same block are
// valid. and of course the distance between u and u is 0

#include <bits/stdc++.h>
using namespace std;
const int inf = 1e9;

#ifdef LOCAL
#include "algo/debug.h"
#endif

#define f first
#define s second
template<class T> using V = vector<T>; 
using vi = V<int>;
using vb = V<bool>;
using vs = V<string>;

#define all(x) begin(x), end(x)
#define rall(x) rbegin(x), rend(x) 
#define pb push_back
#define lb lower_bound
#define ub upper_bound
template<class T> int lwb(V<T>& a, const T& b) { return lb(all(a),b)-begin(a); }
template<class T> int upb(V<T>& a, const T& b) { return ub(all(a),b)-begin(a); }

// dist_to(src class in m, dest layer, dest layer class)
// dist_from(src layer, src class, dest class in m)
const int max_k = 5, max_n = 5e4;
int k, n, m, q, dist_to[max_k][max_n][max_k], dist_from[max_n][max_k][max_k];
const int max_q = 10000;
int ans[max_q];
array<int, 2> queries[max_q];
V<array<int, 2>> g[max_n][max_k];

void dnc(int l, int r, vi query_inds) {
    if (l == r-1) {
        for (int ind : query_inds) {
            auto [l, r] = queries[ind];
            if (l/k != r/k) while (true);
            ans[ind] = l == r ? 0 : -1;
        }
        return;
    }

    int m = (l+r)/2;
    {
        for (int from = 0; from < k; from++) {
            for (int i = m; i < r; i++) {
                fill(all(dist_to[from][i]), inf);
            }
        }
        for (int from = 0; from < k; from++) {
            dist_to[from][m][from] = 0;
            for (int i = m; i < r-1; i++) {
                for (int now = 0; now < k; now++) {
                    for (auto [w, nxt] : g[i][now]) {
                        dist_to[from][i+1][nxt] = min(dist_to[from][i+1][nxt], dist_to[from][i][now]+w);
                    }
                }
            }
        }
    }
    {
        for (int src_layer = l; src_layer <= m; src_layer++) {
            for (int src_class = 0; src_class < k; src_class++) {
                fill(all(dist_from[src_layer][src_class]), inf);
            }
        }
        for (int dest_class = 0; dest_class < k; dest_class++) {
            dist_from[m][dest_class][dest_class] = 0;
            for (int src_layer = m-1; src_layer >= l; src_layer--) {
                for (int src_class = 0; src_class < k; src_class++) {
                    for (auto [w, nxt_class] : g[src_layer][src_class]) {
                        dist_from[src_layer][src_class][dest_class] = min(
                            dist_from[src_layer][src_class][dest_class],
                            w+dist_from[src_layer+1][nxt_class][dest_class]
                        );
                    }
                }
            }
        }
    }

    vi todo[2];
    for (int ind : query_inds) {
        auto [l, r] = queries[ind];
        if (l/k <= m && m <= r/k) {
            int res = inf;
            for (int m_class = 0; m_class < k; m_class++) {
                res = min(res, dist_from[l/k][l%k][m_class]+dist_to[m_class][r/k][r%k]);
            }
            if (res == inf) res = -1;
            ans[ind] = res;
        } else {
            todo[l/k >= m].pb(ind);
        }
    }
    dnc(l, m, todo[0]);
    dnc(m, r, todo[1]);
}

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

    for (int i = 0; i < q; i++) {
        cin >> queries[i][0] >> queries[i][1];
    }
    vi query_inds(q); iota(all(query_inds), 0);

    dnc(0, (n-1)/k+1, query_inds);
    for (int i = 0; i < q; i++) cout << ans[i] << '\n';
}

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

Subtask #1
7.0 / 7.0

# 결과 실행 시간 메모리 Grader output
1 Correct 23 ms 14680 KB Output is correct
2 Correct 3 ms 8796 KB Output is correct
3 Correct 2 ms 8796 KB Output is correct
4 Correct 3 ms 8796 KB Output is correct
5 Correct 2 ms 8796 KB Output is correct
6 Correct 2 ms 8796 KB Output is correct
7 Correct 2 ms 8796 KB Output is correct
8 Correct 22 ms 14684 KB Output is correct
9 Correct 23 ms 14580 KB Output is correct
10 Correct 11 ms 12892 KB Output is correct

Subtask #2
10.0 / 10.0

# 결과 실행 시간 메모리 Grader output
1 Correct 35 ms 14612 KB Output is correct
2 Correct 2 ms 8792 KB Output is correct
3 Correct 2 ms 8796 KB Output is correct
4 Correct 2 ms 10844 KB Output is correct
5 Correct 2 ms 10844 KB Output is correct
6 Correct 2 ms 10844 KB Output is correct
7 Correct 4 ms 9052 KB Output is correct
8 Correct 6 ms 9048 KB Output is correct
9 Correct 22 ms 14684 KB Output is correct
10 Correct 53 ms 15452 KB Output is correct
11 Correct 43 ms 15012 KB Output is correct
12 Correct 35 ms 14580 KB Output is correct
13 Correct 59 ms 15696 KB Output is correct
14 Correct 31 ms 14676 KB Output is correct
15 Correct 33 ms 14428 KB Output is correct
16 Correct 33 ms 14428 KB Output is correct

Subtask #3
8.0 / 8.0

# 결과 실행 시간 메모리 Grader output
1 Correct 2 ms 8796 KB Output is correct
2 Correct 2 ms 8796 KB Output is correct
3 Correct 2 ms 10844 KB Output is correct
4 Correct 2 ms 10844 KB Output is correct
5 Correct 2 ms 10996 KB Output is correct
6 Correct 2 ms 8856 KB Output is correct
7 Correct 2 ms 8796 KB Output is correct
8 Correct 3 ms 10844 KB Output is correct
9 Correct 3 ms 10844 KB Output is correct
10 Correct 20 ms 15316 KB Output is correct
11 Correct 34 ms 15964 KB Output is correct
12 Correct 49 ms 17532 KB Output is correct
13 Correct 55 ms 18004 KB Output is correct
14 Correct 44 ms 16724 KB Output is correct
15 Correct 35 ms 15536 KB Output is correct
16 Correct 33 ms 15444 KB Output is correct

Subtask #4
31.0 / 31.0

# 결과 실행 시간 메모리 Grader output
1 Correct 2 ms 8796 KB Output is correct
2 Correct 2 ms 8796 KB Output is correct
3 Correct 2 ms 10844 KB Output is correct
4 Correct 2 ms 10844 KB Output is correct
5 Correct 2 ms 10996 KB Output is correct
6 Correct 2 ms 8856 KB Output is correct
7 Correct 2 ms 8796 KB Output is correct
8 Correct 3 ms 10844 KB Output is correct
9 Correct 3 ms 10844 KB Output is correct
10 Correct 20 ms 15316 KB Output is correct
11 Correct 34 ms 15964 KB Output is correct
12 Correct 49 ms 17532 KB Output is correct
13 Correct 55 ms 18004 KB Output is correct
14 Correct 44 ms 16724 KB Output is correct
15 Correct 35 ms 15536 KB Output is correct
16 Correct 33 ms 15444 KB Output is correct
17 Correct 34 ms 15952 KB Output is correct
18 Correct 2 ms 8796 KB Output is correct
19 Correct 2 ms 8796 KB Output is correct
20 Correct 2 ms 10844 KB Output is correct
21 Correct 2 ms 10844 KB Output is correct
22 Correct 2 ms 10844 KB Output is correct
23 Correct 3 ms 8796 KB Output is correct
24 Correct 3 ms 8800 KB Output is correct
25 Correct 4 ms 11120 KB Output is correct
26 Correct 5 ms 11100 KB Output is correct
27 Correct 29 ms 15196 KB Output is correct
28 Correct 50 ms 17488 KB Output is correct
29 Correct 55 ms 18176 KB Output is correct
30 Correct 45 ms 16724 KB Output is correct

Subtask #5
44.0 / 44.0

# 결과 실행 시간 메모리 Grader output
1 Correct 23 ms 14680 KB Output is correct
2 Correct 3 ms 8796 KB Output is correct
3 Correct 2 ms 8796 KB Output is correct
4 Correct 3 ms 8796 KB Output is correct
5 Correct 2 ms 8796 KB Output is correct
6 Correct 2 ms 8796 KB Output is correct
7 Correct 2 ms 8796 KB Output is correct
8 Correct 22 ms 14684 KB Output is correct
9 Correct 23 ms 14580 KB Output is correct
10 Correct 11 ms 12892 KB Output is correct
11 Correct 35 ms 14612 KB Output is correct
12 Correct 2 ms 8792 KB Output is correct
13 Correct 2 ms 8796 KB Output is correct
14 Correct 2 ms 10844 KB Output is correct
15 Correct 2 ms 10844 KB Output is correct
16 Correct 2 ms 10844 KB Output is correct
17 Correct 4 ms 9052 KB Output is correct
18 Correct 6 ms 9048 KB Output is correct
19 Correct 22 ms 14684 KB Output is correct
20 Correct 53 ms 15452 KB Output is correct
21 Correct 43 ms 15012 KB Output is correct
22 Correct 35 ms 14580 KB Output is correct
23 Correct 59 ms 15696 KB Output is correct
24 Correct 31 ms 14676 KB Output is correct
25 Correct 33 ms 14428 KB Output is correct
26 Correct 33 ms 14428 KB Output is correct
27 Correct 2 ms 8796 KB Output is correct
28 Correct 2 ms 8796 KB Output is correct
29 Correct 2 ms 10844 KB Output is correct
30 Correct 2 ms 10844 KB Output is correct
31 Correct 2 ms 10996 KB Output is correct
32 Correct 2 ms 8856 KB Output is correct
33 Correct 2 ms 8796 KB Output is correct
34 Correct 3 ms 10844 KB Output is correct
35 Correct 3 ms 10844 KB Output is correct
36 Correct 20 ms 15316 KB Output is correct
37 Correct 34 ms 15964 KB Output is correct
38 Correct 49 ms 17532 KB Output is correct
39 Correct 55 ms 18004 KB Output is correct
40 Correct 44 ms 16724 KB Output is correct
41 Correct 35 ms 15536 KB Output is correct
42 Correct 33 ms 15444 KB Output is correct
43 Correct 34 ms 15952 KB Output is correct
44 Correct 2 ms 8796 KB Output is correct
45 Correct 2 ms 8796 KB Output is correct
46 Correct 2 ms 10844 KB Output is correct
47 Correct 2 ms 10844 KB Output is correct
48 Correct 2 ms 10844 KB Output is correct
49 Correct 3 ms 8796 KB Output is correct
50 Correct 3 ms 8800 KB Output is correct
51 Correct 4 ms 11120 KB Output is correct
52 Correct 5 ms 11100 KB Output is correct
53 Correct 29 ms 15196 KB Output is correct
54 Correct 50 ms 17488 KB Output is correct
55 Correct 55 ms 18176 KB Output is correct
56 Correct 45 ms 16724 KB Output is correct
57 Correct 84 ms 19024 KB Output is correct
58 Correct 23 ms 15448 KB Output is correct
59 Correct 36 ms 16212 KB Output is correct