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Submission #254384

# Submission time Handle Problem Language Result Execution time Memory
254384 2020-07-29T23:19:08 Z Sorting Olympic Bus (JOI20_ho_t4) C++14
100 / 100
 356 ms 4736 KB 
#include <bits/stdc++.h>

using namespace std;

const int k_N = 200 + 3;
const int k_M = 5e4 + 3;
const long long k_Inf = 1e17;

int n, m;
long long dist[k_N][k_N];
array<int, 4> edges[k_M];

vector<array<int, 3>> adj[k_N], adj_rev[k_N];
long long d[k_N];
bool in_q[k_N];

bool f1_[k_M], f_n[k_M], f_1[k_M], fn_[k_M];
int par_edge[k_N];

void spfa(int from, int forbidden_idx, vector<array<int, 3>> *adj){
    queue<int> q;

    for(int i = 1; i <= n; ++i){
        d[i] = k_Inf;
        in_q[i] = false;
        par_edge[i] = -1;
    }

    d[from] = 0;
    q.push(from);
    in_q[from] = true;

    while(!q.empty()){
        int u = q.front();
        q.pop();
        in_q[u] = false;

        for(auto [to, cost, idx]: adj[u]){
            if(idx == forbidden_idx) continue;
            long long new_d = d[u] + cost;
            if(new_d < d[to]){
                d[to] = new_d;
                par_edge[to] = idx;
                if(!in_q[to]){
                    q.push(to);
                    in_q[to] = true;
                }
            }
        }
    }
}

void do_spfa(int from, bool rev, bool *arr){
    if(!rev) spfa(from, -1, adj);
    else spfa(from, -1, adj_rev);

    for(int i = 1; i <= n; ++i)
        if(par_edge[i] != -1)
            arr[par_edge[i]] = true; 
}

int main(){
    ios::sync_with_stdio(false);
    cin.tie(NULL);

    cin >> n >> m;

    for(int i = 1; i <= n; ++i)
        for(int j = 1; j <= n; ++j)
            dist[i][j] = (i == j) ? 0 : k_Inf;

    for(int i = 0; i < m; ++i){
        array<int, 4> &e = edges[i];
        for(int j = 0; j < 4; ++j)
            cin >> e[j];
        dist[e[0]][e[1]] = min(dist[e[0]][e[1]], (long long)e[2]);

        adj[e[0]].push_back({e[1], e[2], i});
        adj_rev[e[1]].push_back({e[0], e[2], i});
    }

    do_spfa(1, false, f1_);
    do_spfa(1, true, f_1);
    do_spfa(n, false, fn_);
    do_spfa(n, true, f_n);

    for(int i = 1; i <= n; ++i)
        for(int j = 1; j <= n; ++j)
            for(int k = 1; k <= n; ++k)
                if(dist[j][i] + dist[i][k] < dist[j][k])
                    dist[j][k] = dist[j][i] + dist[i][k];

    long long ans = k_Inf;
    ans = min(ans, dist[1][n] + dist[n][1]);

    for(int i = 0; i < m; ++i){


        auto [a, b, c, dd] = edges[i];
        long long curr = k_Inf;

        curr = min(curr, dist[1][n] + dist[n][b] + dist[a][1] + c + dd);
        curr = min(curr, dist[n][1] + dist[1][b] + dist[a][n] + c + dd);
        curr = min(curr, dist[n][b] + dist[a][1] + c + dist[1][b] + dist[a][n] + c + dd);

        if(curr < ans){
            long long _1n, _n1, _1b, _an, _nb, _a1;
            curr = k_Inf;

            if(f1_[i]){
                spfa(1, i, adj);
                _1n = d[n];
                _1b = d[b];
            }
            else{
                _1n = dist[1][n];
                _1b = dist[1][b];
            }

            if(fn_[i]){
                spfa(n, i, adj);
                _n1 = d[1];
                _nb = d[b];
            }
            else{
                _n1 = dist[n][1];
                _nb = dist[n][b];
            }

            if(f_n[i]){
                spfa(n, i, adj_rev);
                _an = d[a];
            }
            else _an = dist[a][n];

            if(f_1[i]){
                spfa(1, i, adj_rev);
                _a1 = d[a];
            }
            else _a1 = dist[a][1];

            curr = min(curr, _1n + _nb + _a1 + c + dd);
            curr = min(curr, _n1 + _1b + _an + c + dd);
            curr = min(curr, _nb + _a1 + c + _1b + _an + c + dd);

            //cout << curr << " - " << i << endl;

            ans = min(ans, curr);
        }
    }

    if(ans == k_Inf) ans = -1;
    cout << ans << "\n";
}

Compilation message

ho_t4.cpp: In function 'void spfa(int, int, std::vector<std::array<int, 3> >*)':
ho_t4.cpp:38:18: warning: decomposition declaration only available with -std=c++1z or -std=gnu++1z
         for(auto [to, cost, idx]: adj[u]){
                  ^
ho_t4.cpp: In function 'int main()':
ho_t4.cpp:99:14: warning: decomposition declaration only available with -std=c++1z or -std=gnu++1z
         auto [a, b, c, dd] = edges[i];
              ^

Subtask #1
5.0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 8 ms 768 KB Output is correct
2 Correct 8 ms 768 KB Output is correct
3 Correct 11 ms 768 KB Output is correct
4 Correct 10 ms 768 KB Output is correct
5 Correct 2 ms 512 KB Output is correct
6 Correct 7 ms 768 KB Output is correct
7 Correct 0 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 27 ms 768 KB Output is correct
11 Correct 30 ms 768 KB Output is correct
12 Correct 13 ms 768 KB Output is correct
13 Correct 9 ms 768 KB Output is correct
14 Correct 9 ms 768 KB Output is correct
15 Correct 10 ms 768 KB Output is correct
16 Correct 10 ms 768 KB Output is correct

Subtask #2
11.0 / 11.0

# Verdict Execution time Memory Grader output
1 Correct 35 ms 3584 KB Output is correct
2 Correct 44 ms 3636 KB Output is correct
3 Correct 40 ms 3576 KB Output is correct
4 Correct 10 ms 768 KB Output is correct
5 Correct 9 ms 768 KB Output is correct
6 Correct 9 ms 768 KB Output is correct
7 Correct 8 ms 640 KB Output is correct
8 Correct 1 ms 384 KB Output is correct
9 Correct 34 ms 3456 KB Output is correct
10 Correct 34 ms 3448 KB Output is correct
11 Correct 35 ms 3576 KB Output is correct
12 Correct 35 ms 3584 KB Output is correct
13 Correct 37 ms 3576 KB Output is correct
14 Correct 36 ms 3840 KB Output is correct

Subtask #3
21.0 / 21.0

# Verdict Execution time Memory Grader output
1 Correct 10 ms 768 KB Output is correct
2 Correct 8 ms 764 KB Output is correct
3 Correct 26 ms 2816 KB Output is correct
4 Correct 8 ms 640 KB Output is correct
5 Correct 35 ms 3456 KB Output is correct
6 Correct 1 ms 384 KB Output is correct
7 Correct 0 ms 384 KB Output is correct
8 Correct 29 ms 3584 KB Output is correct
9 Correct 29 ms 3576 KB Output is correct
10 Correct 30 ms 3584 KB Output is correct
11 Correct 29 ms 3576 KB Output is correct
12 Correct 30 ms 3584 KB Output is correct
13 Correct 0 ms 384 KB Output is correct
14 Correct 0 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 1 ms 384 KB Output is correct
19 Correct 31 ms 3704 KB Output is correct
20 Correct 31 ms 3576 KB Output is correct
21 Correct 29 ms 3452 KB Output is correct
22 Correct 31 ms 3576 KB Output is correct

Subtask #4
63.0 / 63.0

# Verdict Execution time Memory Grader output
1 Correct 8 ms 768 KB Output is correct
2 Correct 8 ms 768 KB Output is correct
3 Correct 11 ms 768 KB Output is correct
4 Correct 10 ms 768 KB Output is correct
5 Correct 2 ms 512 KB Output is correct
6 Correct 7 ms 768 KB Output is correct
7 Correct 0 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 27 ms 768 KB Output is correct
11 Correct 30 ms 768 KB Output is correct
12 Correct 13 ms 768 KB Output is correct
13 Correct 9 ms 768 KB Output is correct
14 Correct 9 ms 768 KB Output is correct
15 Correct 10 ms 768 KB Output is correct
16 Correct 10 ms 768 KB Output is correct
17 Correct 35 ms 3584 KB Output is correct
18 Correct 44 ms 3636 KB Output is correct
19 Correct 40 ms 3576 KB Output is correct
20 Correct 10 ms 768 KB Output is correct
21 Correct 9 ms 768 KB Output is correct
22 Correct 9 ms 768 KB Output is correct
23 Correct 8 ms 640 KB Output is correct
24 Correct 1 ms 384 KB Output is correct
25 Correct 34 ms 3456 KB Output is correct
26 Correct 34 ms 3448 KB Output is correct
27 Correct 35 ms 3576 KB Output is correct
28 Correct 35 ms 3584 KB Output is correct
29 Correct 37 ms 3576 KB Output is correct
30 Correct 36 ms 3840 KB Output is correct
31 Correct 10 ms 768 KB Output is correct
32 Correct 8 ms 764 KB Output is correct
33 Correct 26 ms 2816 KB Output is correct
34 Correct 8 ms 640 KB Output is correct
35 Correct 35 ms 3456 KB Output is correct
36 Correct 1 ms 384 KB Output is correct
37 Correct 0 ms 384 KB Output is correct
38 Correct 29 ms 3584 KB Output is correct
39 Correct 29 ms 3576 KB Output is correct
40 Correct 30 ms 3584 KB Output is correct
41 Correct 29 ms 3576 KB Output is correct
42 Correct 30 ms 3584 KB Output is correct
43 Correct 0 ms 384 KB Output is correct
44 Correct 0 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 1 ms 384 KB Output is correct
49 Correct 31 ms 3704 KB Output is correct
50 Correct 31 ms 3576 KB Output is correct
51 Correct 29 ms 3452 KB Output is correct
52 Correct 31 ms 3576 KB Output is correct
53 Correct 35 ms 3456 KB Output is correct
54 Correct 36 ms 3448 KB Output is correct
55 Correct 35 ms 3584 KB Output is correct
56 Correct 10 ms 768 KB Output is correct
57 Correct 10 ms 768 KB Output is correct
58 Correct 36 ms 2816 KB Output is correct
59 Correct 38 ms 2816 KB Output is correct
60 Correct 40 ms 2816 KB Output is correct
61 Correct 36 ms 2816 KB Output is correct
62 Correct 110 ms 2816 KB Output is correct
63 Correct 232 ms 2848 KB Output is correct
64 Correct 121 ms 2936 KB Output is correct
65 Correct 256 ms 3832 KB Output is correct
66 Correct 356 ms 3832 KB Output is correct
67 Correct 19 ms 3132 KB Output is correct
68 Correct 34 ms 4736 KB Output is correct
69 Correct 35 ms 4728 KB Output is correct
70 Correct 35 ms 4732 KB Output is correct
71 Correct 35 ms 4600 KB Output is correct
72 Correct 35 ms 4728 KB Output is correct
73 Correct 35 ms 4728 KB Output is correct
74 Correct 36 ms 4736 KB Output is correct