oj.uz

Submission #944171

# Submission time Handle Problem Language Result Execution time Memory
944171 2024-03-12T09:28:04 Z tnknguyen_ Commuter Pass (JOI18_commuter_pass) C++14
100 / 100
 275 ms 31040 KB 
#include <bits/stdc++.h>
using namespace std;
#define endl '\n' 
#define pll pair<long long, long long>
 
const int sz = 1e5 + 5;
vector<pll> gr[sz];
long long n, m, S, T, U, V;
long long dp[5][sz];
long long d[5][sz];
 
//constants
long long INF;
long long ST;
 
 
// ------------- FUNCTIONS ------------- //
void Dijkstra(int s, int k){
    priority_queue<pll> q;
    d[k][s] = 0;
    q.push({0, s});
 
    while(q.size()){
        long long w, u;
        tie(w, u) = q.top();
        w = -w;
        q.pop();
 
        if(w > d[k][u]){
            continue;
        }
 
        for(pll p : gr[u]){
            long long v, c;
            tie(v, c) = p;
            if(w + c < d[k][v]){
                d[k][v] = w + c;
                q.push({-d[k][v], v});
            }
        }
    } 
}
 
vector<int> dag[sz];
int vi[sz];
void build_DAG(int v){
    vi[v] = 1;
    for(pll p : gr[v]){
        long long u, c;
        tie(u, c) = p;
        if(d[0][u] + c + d[1][v] == ST){
            dag[u].push_back(v);
            if(vi[u] == 0){
                build_DAG(u);
            }
        }
    }
}

deque<int> tp;
void topo(int u){
    vi[u] = 2;
    for(int v : dag[u]){
        if(vi[v] != 2){
            topo(v);
        }
    }
    tp.push_front(u);
}
 
// ------------- SUBTASK ------------- //
namespace SUB1{
    bool ok(){
        return (S == U);
    }
 
    void solve(){
        Dijkstra(V, 3);
 
        long long ans = 1e18;
        for(int i=1;i<=n;++i){
            if(d[0][i] + d[1][i] == d[0][T]){
                ans = min(ans, d[3][i]);
            }
        }
        cout<<ans;
        //--------------------
        exit(0);
    }
}
 
long long ds2[305][305]; 
namespace SUB2{ // n <= 300
    bool ok(){
        return (n <= 300);
    }
 
    void solve(){
 
        memset(ds2, 63, sizeof(ds2));
        for(int i=1;i<=n;++i){
            ds2[i][i] = 0;
            for(pll p : gr[i]){
                ds2[i][p.first] = p.second;
            }
        }
 
        // Floyd - Warshall
        for(int k=1;k<=n;++k){
            for(int i=1;i<=n;++i){
                for(int j=1;j<=n;++j){
                    ds2[i][j] = min(ds2[i][j], ds2[i][k] + ds2[k][j]);
                }
            }
        }
 
        long long ans = ds2[U][V];
        for(int i=1;i<=n;++i){
            for(int j=1;j<=n;++j){
                if(ds2[S][i] + ds2[i][j] + ds2[j][T] == ST){
                    ans = min(ans, ds2[U][i] + ds2[j][V]);
                    ans = min(ans, ds2[U][j] + ds2[i][V]);
                }
            }
        }
 
        cout<<ans;
        //----------------------
        exit(0);
    }
}
 
namespace SUB3{
    void solve(){
        build_DAG(T);
 
        Dijkstra(U, 3);
        Dijkstra(V, 4); 
        
        memset(dp, 63, sizeof(dp));
        for(int i=1;i<=n;++i){
            dp[1][i] = d[3][i]; //U -> i
            dp[2][i] = d[4][i]; //V -> i
        }
 
        topo(S);

        for(int u : tp){
            for(int v : dag[u]){
                dp[1][v] = min(dp[1][v], dp[1][u]);
                dp[2][v] = min(dp[2][v], dp[2][u]);
            }
        }

        long long ans = d[3][V];
        for(int i=1;i<=n;++i){
            ans = min({ans, dp[1][i] + d[4][i], dp[2][i] + d[3][i]});
        }
        cout<<ans;
    }
}
 
int main() {
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
 
  //  freopen("PATHLIB.inp","r",stdin);
 //   freopen("PATHLIB.out","w",stdout);
 
    cin >> n >> m;
    cin >> S >> T;
    cin >> U >> V;
    for(int i=1;i<=m;++i){
        int u, v, c;
        cin>>u>>v>>c;
        gr[u].push_back({v, c});
        gr[v].push_back({u, c});
    }
 
    memset(d, 63, sizeof(d));
    INF = d[0][0];
 
    Dijkstra(S, 0);
    Dijkstra(T, 1);
    ST = d[0][T];
 
    if(SUB1::ok()){ //S == U
        SUB1::solve();
    }
    if(SUB2::ok()){ //n <= 300
        SUB2::solve();
    }
    SUB3::solve();
 
    return 0;
}

Subtask #1
16.0 / 16.0

# Verdict Execution time Memory Grader output
1 Correct 178 ms 22484 KB Output is correct
2 Correct 179 ms 23964 KB Output is correct
3 Correct 191 ms 24180 KB Output is correct
4 Correct 201 ms 25156 KB Output is correct
5 Correct 219 ms 23924 KB Output is correct
6 Correct 207 ms 25384 KB Output is correct
7 Correct 161 ms 23888 KB Output is correct
8 Correct 163 ms 24052 KB Output is correct
9 Correct 187 ms 24220 KB Output is correct
10 Correct 127 ms 23876 KB Output is correct
11 Correct 50 ms 16988 KB Output is correct
12 Correct 162 ms 24028 KB Output is correct

Subtask #2
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 275 ms 26652 KB Output is correct
2 Correct 217 ms 27092 KB Output is correct
3 Correct 216 ms 26580 KB Output is correct
4 Correct 239 ms 27076 KB Output is correct
5 Correct 219 ms 27612 KB Output is correct
6 Correct 211 ms 30344 KB Output is correct
7 Correct 250 ms 31040 KB Output is correct
8 Correct 229 ms 27100 KB Output is correct
9 Correct 243 ms 27852 KB Output is correct
10 Correct 218 ms 26732 KB Output is correct
11 Correct 84 ms 25936 KB Output is correct
12 Correct 236 ms 30864 KB Output is correct

Subtask #3
24.0 / 24.0

# Verdict Execution time Memory Grader output
1 Correct 32 ms 13400 KB Output is correct
2 Correct 30 ms 11868 KB Output is correct
3 Correct 27 ms 12092 KB Output is correct
4 Correct 38 ms 14780 KB Output is correct
5 Correct 31 ms 13404 KB Output is correct
6 Correct 27 ms 12120 KB Output is correct
7 Correct 32 ms 12188 KB Output is correct
8 Correct 33 ms 12124 KB Output is correct
9 Correct 28 ms 12124 KB Output is correct
10 Correct 31 ms 13400 KB Output is correct
11 Correct 29 ms 11868 KB Output is correct
12 Correct 27 ms 11864 KB Output is correct
13 Correct 27 ms 11868 KB Output is correct
14 Correct 27 ms 12096 KB Output is correct
15 Correct 27 ms 11868 KB Output is correct

Subtask #4
45.0 / 45.0

# Verdict Execution time Memory Grader output
1 Correct 178 ms 22484 KB Output is correct
2 Correct 179 ms 23964 KB Output is correct
3 Correct 191 ms 24180 KB Output is correct
4 Correct 201 ms 25156 KB Output is correct
5 Correct 219 ms 23924 KB Output is correct
6 Correct 207 ms 25384 KB Output is correct
7 Correct 161 ms 23888 KB Output is correct
8 Correct 163 ms 24052 KB Output is correct
9 Correct 187 ms 24220 KB Output is correct
10 Correct 127 ms 23876 KB Output is correct
11 Correct 50 ms 16988 KB Output is correct
12 Correct 162 ms 24028 KB Output is correct
13 Correct 275 ms 26652 KB Output is correct
14 Correct 217 ms 27092 KB Output is correct
15 Correct 216 ms 26580 KB Output is correct
16 Correct 239 ms 27076 KB Output is correct
17 Correct 219 ms 27612 KB Output is correct
18 Correct 211 ms 30344 KB Output is correct
19 Correct 250 ms 31040 KB Output is correct
20 Correct 229 ms 27100 KB Output is correct
21 Correct 243 ms 27852 KB Output is correct
22 Correct 218 ms 26732 KB Output is correct
23 Correct 84 ms 25936 KB Output is correct
24 Correct 236 ms 30864 KB Output is correct
25 Correct 32 ms 13400 KB Output is correct
26 Correct 30 ms 11868 KB Output is correct
27 Correct 27 ms 12092 KB Output is correct
28 Correct 38 ms 14780 KB Output is correct
29 Correct 31 ms 13404 KB Output is correct
30 Correct 27 ms 12120 KB Output is correct
31 Correct 32 ms 12188 KB Output is correct
32 Correct 33 ms 12124 KB Output is correct
33 Correct 28 ms 12124 KB Output is correct
34 Correct 31 ms 13400 KB Output is correct
35 Correct 29 ms 11868 KB Output is correct
36 Correct 27 ms 11864 KB Output is correct
37 Correct 27 ms 11868 KB Output is correct
38 Correct 27 ms 12096 KB Output is correct
39 Correct 27 ms 11868 KB Output is correct
40 Correct 205 ms 24868 KB Output is correct
41 Correct 187 ms 24376 KB Output is correct
42 Correct 183 ms 24344 KB Output is correct
43 Correct 87 ms 26228 KB Output is correct
44 Correct 85 ms 26176 KB Output is correct
45 Correct 209 ms 27796 KB Output is correct
46 Correct 231 ms 27260 KB Output is correct
47 Correct 186 ms 25248 KB Output is correct
48 Correct 86 ms 24196 KB Output is correct
49 Correct 167 ms 24936 KB Output is correct
50 Correct 204 ms 26320 KB Output is correct
51 Correct 200 ms 27356 KB Output is correct