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Submission #958458

# Submission time Handle Problem Language Result Execution time Memory
958458 2024-04-05T20:27:07 Z BhavayGoyal Olympic Bus (JOI20_ho_t4) C++14
0 / 100
 71 ms 11012 KB 
#include <bits/stdc++.h>
using namespace std;

#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace __gnu_pbds;

template<class T> using oset = 
            tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;

#define int long long
#define ld long double
#define ar array
#define vi vector<int>
#define vii vector<vector<int>>
#define pii pair<int, int>
#define pb push_back
#define all(x) x.begin(), x.end()
#define f first
#define s second
#define endl "\n"

const int MOD = 1e9+7;
const int inf = 1e9;
const int linf = 1e15;

const int d4i[4]={-1, 0, 1, 0}, d4j[4]={0, 1, 0, -1};
const int d8i[8]={-1, -1, 0, 1, 1, 1, 0, -1}, d8j[8]={0, 1, 1, 1, 0, -1, -1, -1};

mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());


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

const int N = 205, M = 50005;
int n, m, dist[N][N];
set<pii> g[N];
vii edges, shortestEdges;
map<pair<int, int>, bool> isShort;
map<pii, pii> edge;

pair<vi, vi> 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});
            }
        }
    }
    return {dis, par};
}

void sol() {
    for (int i = 0; i < N; i++) for (int j = 0; j < N; j++) if (i != j) dist[i][j] = linf;

    cin >> n >> m;
    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);
        edge[{a, b}] = {c, d};
        g[a].insert({b, c});
        edges.pb({a, b, c, d});
    }

    pair<vi, vi> x = dijkstra(1); vi dis = x.f, par = x.s;
    int c = n;
    while (par[c]) {
        pii temp = edge[{par[c], c}];
        shortestEdges.pb({par[c], c, temp.f, temp.s});
        isShort[{par[c], c}] = true;
        c = par[c];
    }

    x = dijkstra(n); dis = x.f, par = x.s;
    c = 1;
    while (par[c]) {
        pii temp = edge[{par[c], c}];
        shortestEdges.pb({par[c], c, temp.f, temp.s});
        isShort[{par[c], c}] = true;
        c = par[c];
    }

    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 = 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}]) continue;
        int new1n = dist[1][b] + c + dist[a][n];
        int newn1 = dist[n][b] + c + dist[a][1];
        ans = min(ans, dist[1][n] + newn1 + d);
        ans = min(ans, dist[n][1] + new1n + d);
        ans = min(ans, new1n + newn1 + d);

        // tempy thing
        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]);
        ans = min(ans, A + B + d);
    }

    for (auto i : shortestEdges) {
        int a = i[0], b = i[1], c = i[2], d = i[3];
        g[a].erase({b, c});
        g[b].insert({a, c});
        pair<vi, vi> x = dijkstra(1);
        pair<vi, vi> y = dijkstra(n);
        ans = min(ans, x.f[n] + y.f[1] + d);
        g[b].erase({a, c});
        g[a].insert({b, c});
    }

    cout << (ans>=1e10?-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
0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 9 ms 1112 KB Output is correct
2 Correct 8 ms 860 KB Output is correct
3 Correct 9 ms 1068 KB Output is correct
4 Correct 10 ms 1272 KB Output is correct
5 Correct 1 ms 796 KB Output is correct
6 Correct 8 ms 860 KB Output is correct
7 Correct 1 ms 604 KB Output is correct
8 Correct 1 ms 604 KB Output is correct
9 Incorrect 1 ms 860 KB Output isn't correct
10 Halted 0 ms 0 KB -

Subtask #2
0 / 11.0

# Verdict Execution time Memory Grader output
1 Correct 55 ms 9428 KB Output is correct
2 Correct 71 ms 9472 KB Output is correct
3 Correct 55 ms 9452 KB Output is correct
4 Incorrect 9 ms 1112 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 1116 KB Output is correct
2 Correct 8 ms 860 KB Output is correct
3 Correct 49 ms 9220 KB Output is correct
4 Correct 8 ms 860 KB Output is correct
5 Correct 56 ms 11012 KB Output is correct
6 Correct 1 ms 604 KB Output is correct
7 Correct 1 ms 604 KB Output is correct
8 Correct 53 ms 10156 KB Output is correct
9 Correct 51 ms 9988 KB Output is correct
10 Correct 48 ms 8708 KB Output is correct
11 Correct 48 ms 8964 KB Output is correct
12 Correct 49 ms 8768 KB Output is correct
13 Incorrect 1 ms 600 KB Output isn't correct
14 Halted 0 ms 0 KB -

Subtask #4
0 / 63.0

# Verdict Execution time Memory Grader output
1 Correct 9 ms 1112 KB Output is correct
2 Correct 8 ms 860 KB Output is correct
3 Correct 9 ms 1068 KB Output is correct
4 Correct 10 ms 1272 KB Output is correct
5 Correct 1 ms 796 KB Output is correct
6 Correct 8 ms 860 KB Output is correct
7 Correct 1 ms 604 KB Output is correct
8 Correct 1 ms 604 KB Output is correct
9 Incorrect 1 ms 860 KB Output isn't correct
10 Halted 0 ms 0 KB -