oj.uz

Submission #958482

# Submission time Handle Problem Language Result Execution time Memory
958482 2024-04-05T21:42:51 Z BhavayGoyal Olympic Bus (JOI20_ho_t4) C++14
5 / 100
 76 ms 7692 KB 
#include <bits/stdc++.h>
using namespace std;

#define int long long
#define vi vector<int>
#define vii vector<vector<int>>
#define pii pair<int, int>
#define pb push_back
#define f first
#define s second
#define endl "\n"

const int linf = 1e15;

// -------------------------------------------------- Main Code --------------------------------------------------

const int N = 201, M = 50001;
int n, m;
set<pii> g[N];
vii edges;
map<pair<int, int>, bool> isShort;

void dijkstra(int source) {
    priority_queue<pii, vector<pii>, greater<>> q;
    vi vis(n+1, 0), dis(n+1, linf), par(n+1);
    q.push({0, source});
    dis[source] = 0;
    while (!q.empty()) {
        pii f = q.top(); q.pop();
        int src = f.s;
        if (vis[src]) continue;
        vis[src] = true;

        for (auto child : g[src]) {
            int ch = child.f, wt = child.s;
            if (dis[ch] > dis[src] + wt) {
                par[ch] = src;
                dis[ch] = dis[src] + wt;
                q.push({dis[ch], ch});
            }
        }
    }

    int x = (source==1?n:1);
    while (par[x]) {
        isShort[{par[x], x}] = true;
        x = par[x];
    }
}

int get_dist(int s, int t) {
    vi D(n+1, linf);
    priority_queue<pii, vector<pii>, greater<pii>> pq;
    D[s] = 0;
    pq.emplace(0, s);
    while (pq.size()) {
        pii temp = pq.top(); int x = temp.f, u = temp.s;
        pq.pop();
        if (D[u] == x) {
            for (pii child : g[u]) {
                int v = child.f, wt = child.s;
                if (D[v] > x + wt) {
                    pq.emplace(D[v] = x + wt, v);
                }
            }
        }
    }
    return D[t];
}


void sol() {
    cin >> n >> m;
    vii dist(n+1, vi(n+1, linf));
    for (int i = 1; i <= n; i++) dist[i][i] = 0;

    for (int i = 1; i <= m; i++) {
        int a, b, c, d; cin >> a >> b >> c >> d;
        dist[a][b] = min(dist[a][b], c);
        g[a].insert({b, c});
        edges.pb({a, b, c, d});
    }

    dijkstra(1);
    dijkstra(n);
    
    for (int k = 1; k <= n; ++k) {
        for (int i = 1; i <= n; ++i) {
            for (int j = 1; j <= n; ++j) {
                dist[i][j] = min(dist[i][j], dist[i][k] + dist[k][j]);
            }
        }
    }

    int ans = min(linf, dist[1][n] + dist[n][1]);

    for (auto i : edges) {
        int a = i[0], b = i[1], c = i[2], d = i[3];
        if (isShort[{a, b}]) {
            g[a].erase({b, c});
            g[b].insert({a, c});
            ans = min(ans, get_dist(1, n) + get_dist(n, 1) + d);
            g[b].erase({a, c});
            g[a].insert({b, c});
        }
        else {
            int A = min(dist[1][n], dist[1][b] + c + dist[a][n]);
            int B = min(dist[n][1], dist[n][b] + c + dist[a][1]);
            if (A < linf && B < linf) {
                ans = min(ans, A + B + d);
            }
        }
    }

    cout << (ans==linf?-1:ans) << endl;
}

signed main () {
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);

    int t = 1;
    // cin >> t; 
    while (t--) {
        sol();
    }
    return 0;
}

Subtask #1
5.0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 10 ms 856 KB Output is correct
2 Correct 7 ms 604 KB Output is correct
3 Correct 8 ms 860 KB Output is correct
4 Correct 9 ms 860 KB Output is correct
5 Correct 1 ms 604 KB Output is correct
6 Correct 7 ms 604 KB Output is correct
7 Correct 0 ms 348 KB Output is correct
8 Correct 0 ms 348 KB Output is correct
9 Correct 13 ms 348 KB Output is correct
10 Correct 23 ms 860 KB Output is correct
11 Correct 28 ms 860 KB Output is correct
12 Correct 27 ms 988 KB Output is correct
13 Correct 8 ms 860 KB Output is correct
14 Correct 8 ms 856 KB Output is correct
15 Correct 8 ms 856 KB Output is correct
16 Correct 8 ms 860 KB Output is correct

Subtask #2
0 / 11.0

# Verdict Execution time Memory Grader output
1 Correct 76 ms 6972 KB Output is correct
2 Correct 62 ms 6832 KB Output is correct
3 Correct 75 ms 6956 KB Output is correct
4 Incorrect 9 ms 1016 KB Output isn't correct
5 Halted 0 ms 0 KB -

Subtask #3
0 / 21.0

# Verdict Execution time Memory Grader output
1 Correct 9 ms 860 KB Output is correct
2 Correct 10 ms 588 KB Output is correct
3 Correct 42 ms 6392 KB Output is correct
4 Correct 7 ms 604 KB Output is correct
5 Correct 48 ms 7692 KB Output is correct
6 Correct 0 ms 344 KB Output is correct
7 Correct 0 ms 544 KB Output is correct
8 Correct 39 ms 7108 KB Output is correct
9 Correct 42 ms 7132 KB Output is correct
10 Correct 43 ms 6556 KB Output is correct
11 Correct 40 ms 6416 KB Output is correct
12 Correct 43 ms 6368 KB Output is correct
13 Incorrect 0 ms 344 KB Output isn't correct
14 Halted 0 ms 0 KB -

Subtask #4
0 / 63.0

# Verdict Execution time Memory Grader output
1 Correct 10 ms 856 KB Output is correct
2 Correct 7 ms 604 KB Output is correct
3 Correct 8 ms 860 KB Output is correct
4 Correct 9 ms 860 KB Output is correct
5 Correct 1 ms 604 KB Output is correct
6 Correct 7 ms 604 KB Output is correct
7 Correct 0 ms 348 KB Output is correct
8 Correct 0 ms 348 KB Output is correct
9 Correct 13 ms 348 KB Output is correct
10 Correct 23 ms 860 KB Output is correct
11 Correct 28 ms 860 KB Output is correct
12 Correct 27 ms 988 KB Output is correct
13 Correct 8 ms 860 KB Output is correct
14 Correct 8 ms 856 KB Output is correct
15 Correct 8 ms 856 KB Output is correct
16 Correct 8 ms 860 KB Output is correct
17 Correct 76 ms 6972 KB Output is correct
18 Correct 62 ms 6832 KB Output is correct
19 Correct 75 ms 6956 KB Output is correct
20 Incorrect 9 ms 1016 KB Output isn't correct
21 Halted 0 ms 0 KB -