oj.uz

Submission #310948

# Submission time Handle Problem Language Result Execution time Memory
310948 2020-10-08T18:25:07 Z fishy15 Olympic Bus (JOI20_ho_t4) C++17
37 / 100
 1000 ms 2560 KB 
#include <iostream>
#include <iomanip>
#include <fstream>
#include <vector>
#include <array>
#include <algorithm>
#include <utility>
#include <map>
#include <queue>
#include <set>
#include <cmath>
#include <cstdio>
#include <cstring>

#define ll unsigned long long
#define ld long double
#define eps 1e-8
#define MOD 1000000007

#define INF 0x3f3f3f3f
#define INFLL 0x003f3f3f3f3f3f3f

// change if necessary
#define MAXN 210

using namespace std;

int n, m;
vector<array<int, 3>> adj[MAXN];
vector<array<int, 3>> radj[MAXN];
ll ans = INFLL;

ll dist_1[MAXN];
ll rdist_1[MAXN];
ll dist_n[MAXN];
ll rdist_n[MAXN];
bool vis[MAXN];

void solve(int rem) {
    for (int i = 0; i < n; i++) {
        dist_1[i] = INFLL;
        dist_n[i] = INFLL;
        rdist_1[i] = INFLL;
        rdist_n[i] = INFLL;
    }

    memset(vis, 0, sizeof vis);

    priority_queue<pair<ll, int>, vector<pair<ll, int>>, greater<pair<ll, int>>> pq;
    pq.push({0, 0});
    int cnt = 0;
    while (!pq.empty()) {
        auto [d, e] = pq.top();
        pq.pop();
        if (vis[e]) continue;
        vis[e] = true;
        dist_1[e] = d;
        cnt++;
        if (cnt == n) break;
        if (e == rem) continue;
        for (auto [u, c, dd] : adj[e]) {
            if (!vis[u] && d + c < dist_1[u]) {
                pq.push({d + c, u});
                dist_1[u] = d + c;
            }
        }
    }

    memset(vis, 0, sizeof vis);
    pq = {};
    pq.push({0, n - 1});
    cnt = 0;
    while (!pq.empty()) {
        auto [d, e] = pq.top();
        pq.pop();
        if (vis[e]) continue;
        vis[e] = true;
        rdist_n[e] = d;
        cnt++;
        if (cnt == 0) break;
        for (auto [u, c, dd] : radj[e]) {
            if (!vis[u] && d + c < rdist_n[u] && u != rem) {
                pq.push({d + c, u});
                rdist_n[u] = d + c;
            }
        }
    }

    memset(vis, 0, sizeof vis);
    pq = {};
    pq.push({0, n - 1});
    cnt = 0;
    while (!pq.empty()) {
        auto [d, e] = pq.top();
        pq.pop();
        if (vis[e]) continue;
        vis[e] = true;
        dist_n[e] = d;
        cnt++;
        if (cnt == n) break;
        if (e == rem) continue;
        for (auto [u, c, dd] : adj[e]) {
            if (!vis[u] && d + c < dist_n[u]) {
                pq.push({d + c, u});
                dist_n[u] = d + c;
            }
        }
    }

    memset(vis, 0, sizeof vis);
    pq = {};
    pq.push({0, 0});
    cnt = 0;
    while (!pq.empty()) {
        auto [d, e] = pq.top();
        pq.pop();
        if (vis[e]) continue;
        vis[e] = true;
        rdist_1[e] = d;
        cnt++;
        if (cnt == n) break;
        for (auto [u, c, dd] : radj[e]) {
            if (!vis[u] && d + c < rdist_1[u] && u != rem) {
                pq.push({d + c, u});
                rdist_1[u] = d + c;
            }
        }
    }

    ans = min(ans, dist_1[n - 1] + dist_n[0]);
    if (rem == n || adj[rem].empty()) return;

    // path without flipping
    pair<ll, ll> max_to_n = {dist_1[n - 1], dist_1[n - 1]};
    pair<ll, ll> max_to_1 = {dist_n[0], dist_n[0]};
    pair<ll, ll> r_max_to_1 = {rdist_1[rem], rdist_1[rem]};
    pair<ll, ll> r_max_to_n = {rdist_n[rem], rdist_n[rem]};

    for (const auto &e : adj[rem]) {
        ll to_n = dist_1[rem] + e[1] + rdist_n[e[0]];
        ll to_1 = dist_n[rem] + e[1] + rdist_1[e[0]];

        if (to_n <= max_to_n.first) {
            max_to_n.second = max_to_n.first;
            max_to_n.first = to_n;
        } else if (to_n < max_to_n.second) {
            max_to_n.second = to_n;
        }

        if (to_1 <= max_to_1.first) {
            max_to_1.second = max_to_1.first;
            max_to_1.first = to_1;
        } else if (to_1 < max_to_1.second) {
            max_to_1.second = to_1;
        }

        // no flip best prev path
        ll r_to_n = e[1] + rdist_n[e[0]];
        ll r_to_1 = e[1] + rdist_1[e[0]];

        if (r_to_n <= r_max_to_n.first) {
            r_max_to_n.second = r_max_to_n.first;
            r_max_to_n.first = r_to_n;
        } else if (r_to_n < r_max_to_n.second) {
            r_max_to_n.second = r_to_n;
        }

        if (r_to_1 <= r_max_to_1.first) {
            r_max_to_1.second = r_max_to_1.first;
            r_max_to_1.first = r_to_1;
        } else if (r_to_1 < r_max_to_1.second) {
            r_max_to_1.second = r_to_1;
        }
    }

    // consider flipping this
    for (const auto &e : adj[rem]) {
        ll to_n = dist_1[rem] + e[1] + rdist_n[e[0]];
        ll r_to_n = e[1] + rdist_n[e[0]];
        if (to_n == max_to_n.first) {
            to_n = max_to_n.second;
        } else {
            to_n = max_to_n.first;
        }
        if (r_to_n == r_max_to_n.first) {
            r_to_n = r_max_to_n.second;
        } else {
            r_to_n = r_max_to_n.first;
        }
        to_n = min(to_n, dist_1[e[0]] + e[1] + r_to_n);

        ll to_1 = dist_n[rem] + e[1] + rdist_1[e[0]];
        ll r_to_1 = e[1] + rdist_1[e[0]];
        if (to_1 == max_to_1.first) {
            to_1 = max_to_1.second;
        } else {
            to_1 = max_to_1.first;
        }
        if (r_to_1 == r_max_to_1.first) {
            r_to_1 = r_max_to_1.second;
        } else {
            r_to_1 = r_max_to_1.first;
        }
        to_1 = min(to_1, dist_n[e[0]] + e[1] + r_to_1);

        ans = min(ans, to_n + to_1 + e[2]);
    }
}

int main() {
    cin.tie(0)->sync_with_stdio(0);

    cin >> n >> m;
    for (int i = 0; i < m; i++) {
        int u, v, c, d; cin >> u >> v >> c >> d;
        u--; v--;
        adj[u].push_back({v, c, d});
        radj[v].push_back({u, c, d});
    }

    for (int i = 0; i <= n; i++) {
        solve(i);
    }

    if (ans == INFLL) {
        cout << "-1\n";
    } else {
        cout << ans << '\n';
    }

    return 0;
}

Subtask #1
5.0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 18 ms 384 KB Output is correct
2 Correct 1 ms 384 KB Output is correct
3 Correct 27 ms 632 KB Output is correct
4 Correct 26 ms 384 KB Output is correct
5 Correct 2 ms 384 KB Output is correct
6 Correct 2 ms 384 KB Output is correct
7 Correct 1 ms 384 KB Output is correct
8 Correct 0 ms 384 KB Output is correct
9 Correct 1 ms 384 KB Output is correct
10 Correct 35 ms 384 KB Output is correct
11 Correct 34 ms 384 KB Output is correct
12 Correct 34 ms 448 KB Output is correct
13 Correct 9 ms 384 KB Output is correct
14 Correct 18 ms 384 KB Output is correct
15 Correct 16 ms 512 KB Output is correct
16 Correct 17 ms 384 KB Output is correct

Subtask #2
11.0 / 11.0

# Verdict Execution time Memory Grader output
1 Correct 203 ms 2352 KB Output is correct
2 Correct 211 ms 2304 KB Output is correct
3 Correct 204 ms 2304 KB Output is correct
4 Correct 28 ms 384 KB Output is correct
5 Correct 15 ms 384 KB Output is correct
6 Correct 4 ms 384 KB Output is correct
7 Correct 1 ms 384 KB Output is correct
8 Correct 1 ms 384 KB Output is correct
9 Correct 93 ms 2176 KB Output is correct
10 Correct 96 ms 2176 KB Output is correct
11 Correct 162 ms 2304 KB Output is correct
12 Correct 164 ms 2296 KB Output is correct
13 Correct 166 ms 2304 KB Output is correct
14 Correct 163 ms 2560 KB Output is correct

Subtask #3
21.0 / 21.0

# Verdict Execution time Memory Grader output
1 Correct 18 ms 384 KB Output is correct
2 Correct 3 ms 384 KB Output is correct
3 Correct 170 ms 1784 KB Output is correct
4 Correct 2 ms 384 KB Output is correct
5 Correct 211 ms 2176 KB Output is correct
6 Correct 1 ms 384 KB Output is correct
7 Correct 0 ms 384 KB Output is correct
8 Correct 82 ms 2176 KB Output is correct
9 Correct 81 ms 2176 KB Output is correct
10 Correct 162 ms 2296 KB Output is correct
11 Correct 164 ms 2176 KB Output is correct
12 Correct 164 ms 2296 KB Output is correct
13 Correct 0 ms 384 KB Output is correct
14 Correct 0 ms 384 KB Output is correct
15 Correct 1 ms 384 KB Output is correct
16 Correct 0 ms 384 KB Output is correct
17 Correct 0 ms 384 KB Output is correct
18 Correct 0 ms 384 KB Output is correct
19 Correct 162 ms 2552 KB Output is correct
20 Correct 166 ms 2304 KB Output is correct
21 Correct 168 ms 2176 KB Output is correct
22 Correct 164 ms 2424 KB Output is correct

Subtask #4
0 / 63.0

# Verdict Execution time Memory Grader output
1 Correct 18 ms 384 KB Output is correct
2 Correct 1 ms 384 KB Output is correct
3 Correct 27 ms 632 KB Output is correct
4 Correct 26 ms 384 KB Output is correct
5 Correct 2 ms 384 KB Output is correct
6 Correct 2 ms 384 KB Output is correct
7 Correct 1 ms 384 KB Output is correct
8 Correct 0 ms 384 KB Output is correct
9 Correct 1 ms 384 KB Output is correct
10 Correct 35 ms 384 KB Output is correct
11 Correct 34 ms 384 KB Output is correct
12 Correct 34 ms 448 KB Output is correct
13 Correct 9 ms 384 KB Output is correct
14 Correct 18 ms 384 KB Output is correct
15 Correct 16 ms 512 KB Output is correct
16 Correct 17 ms 384 KB Output is correct
17 Correct 203 ms 2352 KB Output is correct
18 Correct 211 ms 2304 KB Output is correct
19 Correct 204 ms 2304 KB Output is correct
20 Correct 28 ms 384 KB Output is correct
21 Correct 15 ms 384 KB Output is correct
22 Correct 4 ms 384 KB Output is correct
23 Correct 1 ms 384 KB Output is correct
24 Correct 1 ms 384 KB Output is correct
25 Correct 93 ms 2176 KB Output is correct
26 Correct 96 ms 2176 KB Output is correct
27 Correct 162 ms 2304 KB Output is correct
28 Correct 164 ms 2296 KB Output is correct
29 Correct 166 ms 2304 KB Output is correct
30 Correct 163 ms 2560 KB Output is correct
31 Correct 18 ms 384 KB Output is correct
32 Correct 3 ms 384 KB Output is correct
33 Correct 170 ms 1784 KB Output is correct
34 Correct 2 ms 384 KB Output is correct
35 Correct 211 ms 2176 KB Output is correct
36 Correct 1 ms 384 KB Output is correct
37 Correct 0 ms 384 KB Output is correct
38 Correct 82 ms 2176 KB Output is correct
39 Correct 81 ms 2176 KB Output is correct
40 Correct 162 ms 2296 KB Output is correct
41 Correct 164 ms 2176 KB Output is correct
42 Correct 164 ms 2296 KB Output is correct
43 Correct 0 ms 384 KB Output is correct
44 Correct 0 ms 384 KB Output is correct
45 Correct 1 ms 384 KB Output is correct
46 Correct 0 ms 384 KB Output is correct
47 Correct 0 ms 384 KB Output is correct
48 Correct 0 ms 384 KB Output is correct
49 Correct 162 ms 2552 KB Output is correct
50 Correct 166 ms 2304 KB Output is correct
51 Correct 168 ms 2176 KB Output is correct
52 Correct 164 ms 2424 KB Output is correct
53 Correct 276 ms 2216 KB Output is correct
54 Correct 271 ms 2304 KB Output is correct
55 Correct 272 ms 2296 KB Output is correct
56 Correct 26 ms 384 KB Output is correct
57 Correct 27 ms 384 KB Output is correct
58 Correct 254 ms 1784 KB Output is correct
59 Correct 260 ms 1784 KB Output is correct
60 Correct 259 ms 1664 KB Output is correct
61 Correct 248 ms 1864 KB Output is correct
62 Correct 254 ms 1784 KB Output is correct
63 Correct 260 ms 1664 KB Output is correct
64 Execution timed out 1088 ms 2508 KB Time limit exceeded
65 Halted 0 ms 0 KB -