oj.uz

Submission #944127

# Submission time Handle Problem Language Result Execution time Memory
944127 2024-03-12T08:46:23 Z tnknguyen_ Commuter Pass (JOI18_commuter_pass) C++14
40 / 100
 224 ms 27592 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);
            }
        }
    }
}

void topo(int u){
    vi[u] = 2;
    for(int v : dag[u]){
        dp[1][u] = min(dp[1][u], dp[1][v]);
        dp[2][u] = min(dp[2][u], dp[2][v]);

        if(vi[v] != 2){
            topo(v);
        }
    }
}

// ------------- 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];
            dp[2][i] = d[4][i]; 
        }

        topo(S);
        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 174 ms 25384 KB Output is correct
2 Correct 159 ms 23964 KB Output is correct
3 Correct 150 ms 25180 KB Output is correct
4 Correct 174 ms 27456 KB Output is correct
5 Correct 145 ms 26224 KB Output is correct
6 Correct 180 ms 27592 KB Output is correct
7 Correct 172 ms 26408 KB Output is correct
8 Correct 171 ms 26320 KB Output is correct
9 Correct 183 ms 26828 KB Output is correct
10 Correct 134 ms 26496 KB Output is correct
11 Correct 54 ms 18296 KB Output is correct
12 Correct 184 ms 26624 KB Output is correct

Subtask #2
0 / 15.0

# Verdict Execution time Memory Grader output
1 Incorrect 224 ms 26636 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #3
24.0 / 24.0

# Verdict Execution time Memory Grader output
1 Correct 33 ms 13400 KB Output is correct
2 Correct 28 ms 11868 KB Output is correct
3 Correct 29 ms 11864 KB Output is correct
4 Correct 42 ms 15192 KB Output is correct
5 Correct 34 ms 13660 KB Output is correct
6 Correct 29 ms 12120 KB Output is correct
7 Correct 32 ms 12124 KB Output is correct
8 Correct 30 ms 12120 KB Output is correct
9 Correct 28 ms 12120 KB Output is correct
10 Correct 35 ms 13660 KB Output is correct
11 Correct 31 ms 12368 KB Output is correct
12 Correct 29 ms 11868 KB Output is correct
13 Correct 32 ms 11872 KB Output is correct
14 Correct 31 ms 12120 KB Output is correct
15 Correct 29 ms 12124 KB Output is correct

Subtask #4
0 / 45.0

# Verdict Execution time Memory Grader output
1 Correct 174 ms 25384 KB Output is correct
2 Correct 159 ms 23964 KB Output is correct
3 Correct 150 ms 25180 KB Output is correct
4 Correct 174 ms 27456 KB Output is correct
5 Correct 145 ms 26224 KB Output is correct
6 Correct 180 ms 27592 KB Output is correct
7 Correct 172 ms 26408 KB Output is correct
8 Correct 171 ms 26320 KB Output is correct
9 Correct 183 ms 26828 KB Output is correct
10 Correct 134 ms 26496 KB Output is correct
11 Correct 54 ms 18296 KB Output is correct
12 Correct 184 ms 26624 KB Output is correct
13 Incorrect 224 ms 26636 KB Output isn't correct
14 Halted 0 ms 0 KB -