oj.uz

Submission #310949

# Submission time Handle Problem Language Result Execution time Memory
310949 2020-10-08T18:27:38 Z fishy15 Olympic Bus (JOI20_ho_t4) C++17
37 / 100
 1000 ms 2576 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];

priority_queue<pair<ll, int>, vector<pair<ll, int>>, greater<pair<ll, int>>> pq;

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);
    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 512 KB Output is correct
2 Correct 2 ms 512 KB Output is correct
3 Correct 25 ms 384 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 36 ms 384 KB Output is correct
13 Correct 7 ms 384 KB Output is correct
14 Correct 19 ms 384 KB Output is correct
15 Correct 16 ms 384 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 199 ms 2348 KB Output is correct
2 Correct 202 ms 2296 KB Output is correct
3 Correct 202 ms 2424 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 95 ms 2176 KB Output is correct
10 Correct 94 ms 2176 KB Output is correct
11 Correct 158 ms 2304 KB Output is correct
12 Correct 161 ms 2304 KB Output is correct
13 Correct 162 ms 2304 KB Output is correct
14 Correct 164 ms 2576 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 174 ms 1664 KB Output is correct
4 Correct 3 ms 384 KB Output is correct
5 Correct 213 ms 2348 KB Output is correct
6 Correct 1 ms 384 KB Output is correct
7 Correct 0 ms 384 KB Output is correct
8 Correct 80 ms 2176 KB Output is correct
9 Correct 83 ms 2176 KB Output is correct
10 Correct 162 ms 2304 KB Output is correct
11 Correct 162 ms 2176 KB Output is correct
12 Correct 162 ms 2304 KB Output is correct
13 Correct 0 ms 384 KB Output is correct
14 Correct 1 ms 384 KB Output is correct
15 Correct 0 ms 384 KB Output is correct
16 Correct 1 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 2432 KB Output is correct
20 Correct 160 ms 2176 KB Output is correct
21 Correct 162 ms 2304 KB Output is correct
22 Correct 165 ms 2424 KB Output is correct

Subtask #4
0 / 63.0

# Verdict Execution time Memory Grader output
1 Correct 18 ms 512 KB Output is correct
2 Correct 2 ms 512 KB Output is correct
3 Correct 25 ms 384 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 36 ms 384 KB Output is correct
13 Correct 7 ms 384 KB Output is correct
14 Correct 19 ms 384 KB Output is correct
15 Correct 16 ms 384 KB Output is correct
16 Correct 17 ms 384 KB Output is correct
17 Correct 199 ms 2348 KB Output is correct
18 Correct 202 ms 2296 KB Output is correct
19 Correct 202 ms 2424 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 95 ms 2176 KB Output is correct
26 Correct 94 ms 2176 KB Output is correct
27 Correct 158 ms 2304 KB Output is correct
28 Correct 161 ms 2304 KB Output is correct
29 Correct 162 ms 2304 KB Output is correct
30 Correct 164 ms 2576 KB Output is correct
31 Correct 18 ms 384 KB Output is correct
32 Correct 3 ms 384 KB Output is correct
33 Correct 174 ms 1664 KB Output is correct
34 Correct 3 ms 384 KB Output is correct
35 Correct 213 ms 2348 KB Output is correct
36 Correct 1 ms 384 KB Output is correct
37 Correct 0 ms 384 KB Output is correct
38 Correct 80 ms 2176 KB Output is correct
39 Correct 83 ms 2176 KB Output is correct
40 Correct 162 ms 2304 KB Output is correct
41 Correct 162 ms 2176 KB Output is correct
42 Correct 162 ms 2304 KB Output is correct
43 Correct 0 ms 384 KB Output is correct
44 Correct 1 ms 384 KB Output is correct
45 Correct 0 ms 384 KB Output is correct
46 Correct 1 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 2432 KB Output is correct
50 Correct 160 ms 2176 KB Output is correct
51 Correct 162 ms 2304 KB Output is correct
52 Correct 165 ms 2424 KB Output is correct
53 Correct 277 ms 2296 KB Output is correct
54 Correct 270 ms 2304 KB Output is correct
55 Correct 273 ms 2176 KB Output is correct
56 Correct 27 ms 384 KB Output is correct
57 Correct 27 ms 384 KB Output is correct
58 Correct 252 ms 1784 KB Output is correct
59 Correct 257 ms 1664 KB Output is correct
60 Correct 261 ms 1664 KB Output is correct
61 Correct 247 ms 1784 KB Output is correct
62 Correct 256 ms 1664 KB Output is correct
63 Correct 257 ms 1728 KB Output is correct
64 Execution timed out 1098 ms 2412 KB Time limit exceeded
65 Halted 0 ms 0 KB -