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Submission #310961

# Submission time Handle Problem Language Result Execution time Memory
310961 2020-10-08T19:29:32 Z fishy15 Olympic Bus (JOI20_ho_t4) C++17
100 / 100
 207 ms 4224 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 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 adjm[MAXN][MAXN];
ll radjm[MAXN][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);
    int e = 0;
    dist_1[0] = 0;
    while (e != -1) {
        ll d = dist_1[e];
        vis[e] = true;
        if (e != rem) {
            for (int u = 0; u < n; u++) {
                if (!vis[u] && d + adjm[e][u] < dist_1[u]) {
                    dist_1[u] = d + adjm[e][u];
                }
            }
        }
        e = -1;
        ll min_d = INFLL;
        for (int i = 0; i < n; i++) {
            if (!vis[i] && dist_1[i] < min_d) {
                e = i;
                min_d = dist_1[i];
            }
        }
    }

    memset(vis, 0, sizeof vis);
    e = n - 1;
    rdist_n[n - 1] = 0;
    while (e != -1) {
        ll d = rdist_n[e];
        vis[e] = true;
        for (int u = 0; u < n; u++) {
            if (!vis[u] && d + radjm[e][u] < rdist_n[u] && u != rem) {
                rdist_n[u] = d + radjm[e][u];
            }
        }
        e = -1;
        ll min_d = INFLL;
        for (int i = 0; i < n; i++) {
            if (!vis[i] && rdist_n[i] < min_d) {
                e = i;
                min_d = rdist_n[i];
            }
        }
    }

    memset(vis, 0, sizeof vis);
    e = n - 1;
    dist_n[n - 1] = 0;
    while (e != -1) {
        int d = dist_n[e];
        vis[e] = true;
        if (e != rem) {
            for (int u = 0; u < n; u++) {
                if (!vis[u] && d + adjm[e][u] < dist_n[u]) {
                    dist_n[u] = d + adjm[e][u];
                }
            }
        }
        e = -1;
        ll min_d = INFLL;
        for (int i = 0; i < n; i++) {
            if (!vis[i] && dist_n[i] < min_d) {
                e = i;
                min_d = dist_n[i];
            }
        }
    }

    memset(vis, 0, sizeof vis);
    e = 0;
    rdist_1[0] = 0;
    while (e != -1) {
        ll d = rdist_1[e];
        vis[e] = true;
        for (int u = 0; u < n; u++) {
            if (!vis[u] && d + radjm[e][u] < rdist_1[u] && u != rem) {
                rdist_1[u] = d + radjm[e][u];
            }
        }
        e = -1;
        ll min_d = INFLL;
        for (int i = 0; i < n; i++) {
            if (!vis[i] && rdist_1[i] < min_d) {
                e = i;
                min_d = rdist_1[i];
            }
        }
    }

    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 < n; i++) {
        for (int j = 0; j < n; j++) {
            adjm[i][j] = INFLL;
            radjm[i][j] = INFLL;
        }
    }

    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});
        adjm[u][v] = min(adjm[u][v], (ll)c);
        radjm[v][u] = min(radjm[v][u], (ll)c);
    }

    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 107 ms 1024 KB Output is correct
2 Correct 15 ms 1024 KB Output is correct
3 Correct 176 ms 1144 KB Output is correct
4 Correct 180 ms 1024 KB Output is correct
5 Correct 2 ms 512 KB Output is correct
6 Correct 32 ms 1024 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 179 ms 1108 KB Output is correct
11 Correct 181 ms 1024 KB Output is correct
12 Correct 178 ms 1144 KB Output is correct
13 Correct 77 ms 1024 KB Output is correct
14 Correct 129 ms 1024 KB Output is correct
15 Correct 127 ms 1152 KB Output is correct
16 Correct 131 ms 1144 KB Output is correct

Subtask #2
11.0 / 11.0

# Verdict Execution time Memory Grader output
1 Correct 206 ms 2944 KB Output is correct
2 Correct 207 ms 3016 KB Output is correct
3 Correct 207 ms 3064 KB Output is correct
4 Correct 176 ms 1152 KB Output is correct
5 Correct 163 ms 1024 KB Output is correct
6 Correct 57 ms 1024 KB Output is correct
7 Correct 6 ms 1024 KB Output is correct
8 Correct 1 ms 384 KB Output is correct
9 Correct 105 ms 2936 KB Output is correct
10 Correct 106 ms 2816 KB Output is correct
11 Correct 164 ms 3064 KB Output is correct
12 Correct 159 ms 2936 KB Output is correct
13 Correct 157 ms 2944 KB Output is correct
14 Correct 158 ms 3200 KB Output is correct

Subtask #3
21.0 / 21.0

# Verdict Execution time Memory Grader output
1 Correct 107 ms 1144 KB Output is correct
2 Correct 55 ms 1024 KB Output is correct
3 Correct 97 ms 2304 KB Output is correct
4 Correct 36 ms 1024 KB Output is correct
5 Correct 101 ms 2816 KB Output is correct
6 Correct 1 ms 384 KB Output is correct
7 Correct 0 ms 384 KB Output is correct
8 Correct 79 ms 2944 KB Output is correct
9 Correct 76 ms 2944 KB Output is correct
10 Correct 105 ms 3064 KB Output is correct
11 Correct 92 ms 2936 KB Output is correct
12 Correct 87 ms 3072 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 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 99 ms 3064 KB Output is correct
20 Correct 97 ms 2944 KB Output is correct
21 Correct 88 ms 2848 KB Output is correct
22 Correct 94 ms 2936 KB Output is correct

Subtask #4
63.0 / 63.0

# Verdict Execution time Memory Grader output
1 Correct 107 ms 1024 KB Output is correct
2 Correct 15 ms 1024 KB Output is correct
3 Correct 176 ms 1144 KB Output is correct
4 Correct 180 ms 1024 KB Output is correct
5 Correct 2 ms 512 KB Output is correct
6 Correct 32 ms 1024 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 179 ms 1108 KB Output is correct
11 Correct 181 ms 1024 KB Output is correct
12 Correct 178 ms 1144 KB Output is correct
13 Correct 77 ms 1024 KB Output is correct
14 Correct 129 ms 1024 KB Output is correct
15 Correct 127 ms 1152 KB Output is correct
16 Correct 131 ms 1144 KB Output is correct
17 Correct 206 ms 2944 KB Output is correct
18 Correct 207 ms 3016 KB Output is correct
19 Correct 207 ms 3064 KB Output is correct
20 Correct 176 ms 1152 KB Output is correct
21 Correct 163 ms 1024 KB Output is correct
22 Correct 57 ms 1024 KB Output is correct
23 Correct 6 ms 1024 KB Output is correct
24 Correct 1 ms 384 KB Output is correct
25 Correct 105 ms 2936 KB Output is correct
26 Correct 106 ms 2816 KB Output is correct
27 Correct 164 ms 3064 KB Output is correct
28 Correct 159 ms 2936 KB Output is correct
29 Correct 157 ms 2944 KB Output is correct
30 Correct 158 ms 3200 KB Output is correct
31 Correct 107 ms 1144 KB Output is correct
32 Correct 55 ms 1024 KB Output is correct
33 Correct 97 ms 2304 KB Output is correct
34 Correct 36 ms 1024 KB Output is correct
35 Correct 101 ms 2816 KB Output is correct
36 Correct 1 ms 384 KB Output is correct
37 Correct 0 ms 384 KB Output is correct
38 Correct 79 ms 2944 KB Output is correct
39 Correct 76 ms 2944 KB Output is correct
40 Correct 105 ms 3064 KB Output is correct
41 Correct 92 ms 2936 KB Output is correct
42 Correct 87 ms 3072 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 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 99 ms 3064 KB Output is correct
50 Correct 97 ms 2944 KB Output is correct
51 Correct 88 ms 2848 KB Output is correct
52 Correct 94 ms 2936 KB Output is correct
53 Correct 203 ms 2816 KB Output is correct
54 Correct 205 ms 2944 KB Output is correct
55 Correct 207 ms 3064 KB Output is correct
56 Correct 176 ms 1024 KB Output is correct
57 Correct 176 ms 1024 KB Output is correct
58 Correct 203 ms 2424 KB Output is correct
59 Correct 207 ms 2304 KB Output is correct
60 Correct 204 ms 2392 KB Output is correct
61 Correct 205 ms 2428 KB Output is correct
62 Correct 204 ms 2304 KB Output is correct
63 Correct 202 ms 2304 KB Output is correct
64 Correct 201 ms 2680 KB Output is correct
65 Correct 180 ms 3328 KB Output is correct
66 Correct 156 ms 3328 KB Output is correct
67 Correct 18 ms 2748 KB Output is correct
68 Correct 111 ms 4096 KB Output is correct
69 Correct 110 ms 4088 KB Output is correct
70 Correct 160 ms 4088 KB Output is correct
71 Correct 160 ms 3968 KB Output is correct
72 Correct 161 ms 4092 KB Output is correct
73 Correct 157 ms 4224 KB Output is correct
74 Correct 157 ms 4088 KB Output is correct