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답안 #958509

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
958509 2024-04-05T22:41:36 Z BhavayGoyal Olympic Bus (JOI20_ho_t4) C++14
0 / 100
 43 ms 5752 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 inf = 1e15;

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

const int N = 201, M = 50001;
int n, m, aa[M], bb[M], cc[M], dd[M], dis[N], vis[N], dist[N][N], isShort[M];
set<pii> g[N];

void dijkstra(int source) {
    priority_queue<pii, vector<pii>, greater<>> q;
    vi vis(n+1, 0), dis(n+1, inf), par(n+1), idx(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 = cc[child.s];
            if (dis[ch] > dis[src] + wt) {
                par[ch] = src;
                idx[ch] = child.s;
                dis[ch] = dis[src] + wt;
                q.push({dis[ch], ch});
            }
        }
    }

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

int get_dist(int s, int t) {
    vi D(n+1, inf);
    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;
    for (int i = 1; i <= n; i++) for (int j = 1; j <= n; j++) if (i != j) dist[i][j] = inf;

    for (int i = 1; i <= m; i++) {
        cin >> aa[i] >> bb[i] >> cc[i] >> dd[i];
        dist[aa[i]][bb[i]] = min(dist[aa[i]][bb[i]], cc[i]);
        g[aa[i]].insert({bb[i], i});
    }

    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(inf, dist[1][n] + dist[n][1]);

    for (int i = 1; i <= m; i++) {
        int a = aa[i], b = bb[i], c = cc[i], d = dd[i];
        if (isShort[i]) {
            g[a].erase(g[a].find({b, i}));
            g[b].insert({a, i});
            ans = min(ans, get_dist(1, n) + get_dist(n, 1) + d);
            g[b].erase(g[b].find({a, i}));
            g[a].insert({b, i});
        }
        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]);
            ans = min(ans, A + B + d);
        }
    }

    cout << (ans==inf?-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

# 결과 실행 시간 메모리 Grader output
1 Correct 9 ms 2396 KB Output is correct
2 Correct 7 ms 2552 KB Output is correct
3 Correct 8 ms 2396 KB Output is correct
4 Correct 8 ms 2608 KB Output is correct
5 Incorrect 1 ms 2396 KB Output isn't correct
6 Halted 0 ms 0 KB -

Subtask #2
0 / 11.0

# 결과 실행 시간 메모리 Grader output
1 Correct 41 ms 5752 KB Output is correct
2 Incorrect 43 ms 5720 KB Output isn't correct
3 Halted 0 ms 0 KB -

Subtask #3
0 / 21.0

# 결과 실행 시간 메모리 Grader output
1 Correct 10 ms 2396 KB Output is correct
2 Correct 7 ms 2396 KB Output is correct
3 Correct 36 ms 5204 KB Output is correct
4 Correct 7 ms 2396 KB Output is correct
5 Correct 35 ms 5720 KB Output is correct
6 Correct 1 ms 2392 KB Output is correct
7 Correct 1 ms 2396 KB Output is correct
8 Correct 28 ms 5540 KB Output is correct
9 Correct 29 ms 5592 KB Output is correct
10 Correct 34 ms 5716 KB Output is correct
11 Correct 33 ms 5724 KB Output is correct
12 Correct 33 ms 5724 KB Output is correct
13 Incorrect 1 ms 2392 KB Output isn't correct
14 Halted 0 ms 0 KB -

Subtask #4
0 / 63.0

# 결과 실행 시간 메모리 Grader output
1 Correct 9 ms 2396 KB Output is correct
2 Correct 7 ms 2552 KB Output is correct
3 Correct 8 ms 2396 KB Output is correct
4 Correct 8 ms 2608 KB Output is correct
5 Incorrect 1 ms 2396 KB Output isn't correct
6 Halted 0 ms 0 KB -