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Submission #958465

# Submission time Handle Problem Language Result Execution time Memory
958465 2024-04-05T20:33:28 Z BhavayGoyal Olympic Bus (JOI20_ho_t4) C++14
5 / 100
 86 ms 7664 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, dist[N][N];
set<pii> g[N];
vii edges;
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++) 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);
        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}];
        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}];
        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++) {
                if (i == j) dist[i][j] = 0;
                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}]) {
            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});
        }
        else {
            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);
        }
    }

    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;
}

Compilation message

ho_t4.cpp: In function 'void sol()':
ho_t4.cpp:61:13: warning: variable 'temp' set but not used [-Wunused-but-set-variable]
   61 |         pii temp = edge[{par[c], c}];
      |             ^~~~
ho_t4.cpp:69:13: warning: variable 'temp' set but not used [-Wunused-but-set-variable]
   69 |         pii temp = edge[{par[c], c}];
      |             ^~~~

Subtask #1
5.0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 10 ms 860 KB Output is correct
2 Correct 9 ms 604 KB Output is correct
3 Correct 11 ms 944 KB Output is correct
4 Correct 10 ms 860 KB Output is correct
5 Correct 1 ms 860 KB Output is correct
6 Correct 9 ms 836 KB Output is correct
7 Correct 1 ms 600 KB Output is correct
8 Correct 0 ms 604 KB Output is correct
9 Correct 13 ms 860 KB Output is correct
10 Correct 26 ms 1008 KB Output is correct
11 Correct 31 ms 856 KB Output is correct
12 Correct 30 ms 984 KB Output is correct
13 Correct 13 ms 944 KB Output is correct
14 Correct 10 ms 944 KB Output is correct
15 Correct 10 ms 940 KB Output is correct
16 Correct 11 ms 860 KB Output is correct

Subtask #2
0 / 11.0

# Verdict Execution time Memory Grader output
1 Correct 86 ms 6928 KB Output is correct
2 Correct 64 ms 6920 KB Output is correct
3 Correct 70 ms 6912 KB Output is correct
4 Incorrect 12 ms 860 KB Output isn't correct
5 Halted 0 ms 0 KB -

Subtask #3
0 / 21.0

# Verdict Execution time Memory Grader output
1 Correct 10 ms 856 KB Output is correct
2 Correct 9 ms 836 KB Output is correct
3 Correct 46 ms 6600 KB Output is correct
4 Correct 9 ms 604 KB Output is correct
5 Correct 51 ms 7664 KB Output is correct
6 Correct 1 ms 604 KB Output is correct
7 Correct 0 ms 604 KB Output is correct
8 Correct 48 ms 7112 KB Output is correct
9 Correct 41 ms 7176 KB Output is correct
10 Correct 50 ms 6480 KB Output is correct
11 Correct 42 ms 6408 KB Output is correct
12 Correct 44 ms 6392 KB Output is correct
13 Incorrect 0 ms 604 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 860 KB Output is correct
2 Correct 9 ms 604 KB Output is correct
3 Correct 11 ms 944 KB Output is correct
4 Correct 10 ms 860 KB Output is correct
5 Correct 1 ms 860 KB Output is correct
6 Correct 9 ms 836 KB Output is correct
7 Correct 1 ms 600 KB Output is correct
8 Correct 0 ms 604 KB Output is correct
9 Correct 13 ms 860 KB Output is correct
10 Correct 26 ms 1008 KB Output is correct
11 Correct 31 ms 856 KB Output is correct
12 Correct 30 ms 984 KB Output is correct
13 Correct 13 ms 944 KB Output is correct
14 Correct 10 ms 944 KB Output is correct
15 Correct 10 ms 940 KB Output is correct
16 Correct 11 ms 860 KB Output is correct
17 Correct 86 ms 6928 KB Output is correct
18 Correct 64 ms 6920 KB Output is correct
19 Correct 70 ms 6912 KB Output is correct
20 Incorrect 12 ms 860 KB Output isn't correct
21 Halted 0 ms 0 KB -