oj.uz

Submission #923129

# Submission time Handle Problem Language Result Execution time Memory
923129 2024-02-06T17:38:18 Z Camillus Olympic Bus (JOI20_ho_t4) C++17
37 / 100
 1000 ms 6112 KB 
/// @author Camillus
#include <bits/stdc++.h>
#define int long long

using ll = long long;
using namespace std;

int from[50'000];
int to[50'000];
int cost[50'000];
int change[50'000];

static constexpr int INF = 1e17;

int n, m;

vector<pair<int, int>> g[200];
int d_from[200];
int d_to[200];

void dist_from_all(int s) {
    for (int u = 0; u < n; u++) {
        g[u].resize(0);
    }

    for (int i = 0; i < m; i++) {
        g[to[i]].emplace_back(from[i], cost[i]);
    }

    auto d = d_to;
    for (int i = 0; i < n; i++) {
        d[i] = INF;
    }
    d[s] = 0;

    set<pair<int, int>> Q;
    Q.emplace(d[s], s);

    while (!Q.empty()) {
        int u = Q.begin()->second;
        Q.erase(Q.begin());

        for (auto [v, c] : g[u]) {
            if (d[v] > d[u] + c) {
                Q.erase(pair(d[v], v));
                d[v] = d[u] + c;
                Q.emplace(d[v], v);
            }
        }
    }
}

void dist_to_all(int s) {
    for (int u = 0; u < n; u++) {
        g[u].resize(0);
    }

    for (int i = 0; i < m; i++) {
        g[from[i]].emplace_back(to[i], cost[i]);
    }

    auto d = d_from;
    for (int i = 0; i < n; i++) {
        d[i] = INF;
    }
    d[s] = 0;

    set<pair<int, int>> Q;
    Q.emplace(d[s], s);

    while (!Q.empty()) {
        int u = Q.begin()->second;
        Q.erase(Q.begin());

        for (auto [v, c] : g[u]) {
            if (d[v] > d[u] + c) {
                Q.erase(pair(d[v], v));
                d[v] = d[u] + c;
                Q.emplace(d[v], v);
            }
        }
    }
}

int get_cost() {
    int result = 0;

    dist_to_all(0);
    dist_from_all(0);

    return min(INF, d_from[n - 1] + d_to[n - 1]);
}

random_device rd;
mt19937_64 rnd(rd());

signed main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    cin >> n >> m;

    for (int i = 0; i < m; i++) {
        int u, v, c, d;
        cin >> u >> v >> c >> d;
        u--, v--;

        from[i] = u;
        to[i] = v;
        cost[i] = c;
        change[i] = d;
    }

    auto group1 = [&]() -> bool {
        return m <= 1000;
    };

    auto group2 = [&]() -> bool {
        if (m % 2 == 1) {
            return false;
        }

        for (int i = 0; i < m; i += 2) {
            bool condition = from[i] == from[i + 1] && to[i] == to[i + 1] && cost[i] == cost[i + 1];
            if (!condition) {
                return false;
            }
        }

        return true;
    };

    auto group3 = [&]() -> bool {
        for (int i = 0; i < m; i++) {
            if (cost[i] != 0) {
                return false;
            }
        }
        return true;
    };

    vector<vector<int>> d(n, vector<int>(n, INF));
    vector<int> good;

    for (int i = 0; i < m; i++) {
        d[from[i]][to[i]] = min(d[from[i]][to[i]], cost[i]);
    }

    for (int u = 0; u < n; u++) {
        d[u][u] = 0;
    }

    for (int k = 0; k < n; k++) {
        for (int u = 0; u < n; u++) {
            for (int v = 0; v < n; v++) {
                d[u][v] = min(d[u][v], d[u][k] + d[k][v]);
            }
        }
    }

    vector<int> best1(m);
    iota(best1.begin(), best1.end(), 0);
    sort(best1.begin(), best1.end(), [&](int i, int j) -> bool {
        auto val = [&](int x) -> int {
            return d[0][to[x]] + cost[x] + change[x] + d[from[x]][n - 1];
        };
        return val(i) < val(j);
    });
    best1.resize(min(best1.size(), (size_t)300));

    vector<int> best2(m);
    iota(best2.begin(), best2.end(), 0);
    sort(best2.begin(), best2.end(), [&](int i, int j) -> bool {
        auto val = [&](int x) -> int {
            return d[n - 1][to[x]] + cost[x] + change[x] + d[from[x]][0];
        };
        return val(i) < val(j);
    });
    best2.resize(min(best2.size(), (size_t)300));

    vector<int> best;
    for (int i : best1) {
        best.push_back(i);
    }
    for (int i : best2) {
        best.push_back(i);
    }

    sort(best.begin(), best.end());
    best.erase(unique(best.begin(), best.end()), best.end());

    int initial = get_cost();
    int ans = initial;

    for (int i : best) {
        swap(from[i], to[i]);
        ans = min(ans, get_cost() + change[i]);
        swap(from[i], to[i]);
    }

    cout << (ans == INF ? -1 : ans) << '\n';
    return 0;
}

Compilation message

ho_t4.cpp: In function 'long long int get_cost()':
ho_t4.cpp:86:9: warning: unused variable 'result' [-Wunused-variable]
   86 |     int result = 0;
      |         ^~~~~~
ho_t4.cpp: In function 'int main()':
ho_t4.cpp:113:10: warning: variable 'group1' set but not used [-Wunused-but-set-variable]
  113 |     auto group1 = [&]() -> bool {
      |          ^~~~~~
ho_t4.cpp:117:10: warning: variable 'group2' set but not used [-Wunused-but-set-variable]
  117 |     auto group2 = [&]() -> bool {
      |          ^~~~~~
ho_t4.cpp:132:10: warning: variable 'group3' set but not used [-Wunused-but-set-variable]
  132 |     auto group3 = [&]() -> bool {
      |          ^~~~~~

Subtask #1
5.0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 20 ms 916 KB Output is correct
2 Correct 9 ms 600 KB Output is correct
3 Correct 30 ms 936 KB Output is correct
4 Correct 33 ms 864 KB Output is correct
5 Correct 7 ms 604 KB Output is correct
6 Correct 11 ms 600 KB Output is correct
7 Correct 0 ms 348 KB Output is correct
8 Correct 0 ms 348 KB Output is correct
9 Correct 3 ms 604 KB Output is correct
10 Correct 46 ms 932 KB Output is correct
11 Correct 41 ms 916 KB Output is correct
12 Correct 43 ms 936 KB Output is correct
13 Correct 27 ms 856 KB Output is correct
14 Correct 25 ms 868 KB Output is correct
15 Correct 21 ms 864 KB Output is correct
16 Correct 22 ms 788 KB Output is correct

Subtask #2
11.0 / 11.0

# Verdict Execution time Memory Grader output
1 Correct 257 ms 5728 KB Output is correct
2 Correct 326 ms 5652 KB Output is correct
3 Correct 244 ms 5912 KB Output is correct
4 Correct 45 ms 860 KB Output is correct
5 Correct 29 ms 856 KB Output is correct
6 Correct 14 ms 860 KB Output is correct
7 Correct 10 ms 756 KB Output is correct
8 Correct 0 ms 600 KB Output is correct
9 Correct 226 ms 6096 KB Output is correct
10 Correct 231 ms 6112 KB Output is correct
11 Correct 205 ms 5704 KB Output is correct
12 Correct 201 ms 5716 KB Output is correct
13 Correct 216 ms 5720 KB Output is correct
14 Correct 197 ms 5588 KB Output is correct

Subtask #3
21.0 / 21.0

# Verdict Execution time Memory Grader output
1 Correct 20 ms 860 KB Output is correct
2 Correct 10 ms 604 KB Output is correct
3 Correct 125 ms 4304 KB Output is correct
4 Correct 11 ms 604 KB Output is correct
5 Correct 155 ms 5824 KB Output is correct
6 Correct 0 ms 348 KB Output is correct
7 Correct 0 ms 348 KB Output is correct
8 Correct 165 ms 5848 KB Output is correct
9 Correct 166 ms 5888 KB Output is correct
10 Correct 144 ms 5448 KB Output is correct
11 Correct 143 ms 5596 KB Output is correct
12 Correct 146 ms 5456 KB Output is correct
13 Correct 0 ms 344 KB Output is correct
14 Correct 0 ms 348 KB Output is correct
15 Correct 0 ms 348 KB Output is correct
16 Correct 0 ms 348 KB Output is correct
17 Correct 0 ms 344 KB Output is correct
18 Correct 0 ms 348 KB Output is correct
19 Correct 158 ms 5528 KB Output is correct
20 Correct 144 ms 5504 KB Output is correct
21 Correct 145 ms 5460 KB Output is correct
22 Correct 150 ms 5624 KB Output is correct

Subtask #4
0 / 63.0

# Verdict Execution time Memory Grader output
1 Correct 20 ms 916 KB Output is correct
2 Correct 9 ms 600 KB Output is correct
3 Correct 30 ms 936 KB Output is correct
4 Correct 33 ms 864 KB Output is correct
5 Correct 7 ms 604 KB Output is correct
6 Correct 11 ms 600 KB Output is correct
7 Correct 0 ms 348 KB Output is correct
8 Correct 0 ms 348 KB Output is correct
9 Correct 3 ms 604 KB Output is correct
10 Correct 46 ms 932 KB Output is correct
11 Correct 41 ms 916 KB Output is correct
12 Correct 43 ms 936 KB Output is correct
13 Correct 27 ms 856 KB Output is correct
14 Correct 25 ms 868 KB Output is correct
15 Correct 21 ms 864 KB Output is correct
16 Correct 22 ms 788 KB Output is correct
17 Correct 257 ms 5728 KB Output is correct
18 Correct 326 ms 5652 KB Output is correct
19 Correct 244 ms 5912 KB Output is correct
20 Correct 45 ms 860 KB Output is correct
21 Correct 29 ms 856 KB Output is correct
22 Correct 14 ms 860 KB Output is correct
23 Correct 10 ms 756 KB Output is correct
24 Correct 0 ms 600 KB Output is correct
25 Correct 226 ms 6096 KB Output is correct
26 Correct 231 ms 6112 KB Output is correct
27 Correct 205 ms 5704 KB Output is correct
28 Correct 201 ms 5716 KB Output is correct
29 Correct 216 ms 5720 KB Output is correct
30 Correct 197 ms 5588 KB Output is correct
31 Correct 20 ms 860 KB Output is correct
32 Correct 10 ms 604 KB Output is correct
33 Correct 125 ms 4304 KB Output is correct
34 Correct 11 ms 604 KB Output is correct
35 Correct 155 ms 5824 KB Output is correct
36 Correct 0 ms 348 KB Output is correct
37 Correct 0 ms 348 KB Output is correct
38 Correct 165 ms 5848 KB Output is correct
39 Correct 166 ms 5888 KB Output is correct
40 Correct 144 ms 5448 KB Output is correct
41 Correct 143 ms 5596 KB Output is correct
42 Correct 146 ms 5456 KB Output is correct
43 Correct 0 ms 344 KB Output is correct
44 Correct 0 ms 348 KB Output is correct
45 Correct 0 ms 348 KB Output is correct
46 Correct 0 ms 348 KB Output is correct
47 Correct 0 ms 344 KB Output is correct
48 Correct 0 ms 348 KB Output is correct
49 Correct 158 ms 5528 KB Output is correct
50 Correct 144 ms 5504 KB Output is correct
51 Correct 145 ms 5460 KB Output is correct
52 Correct 150 ms 5624 KB Output is correct
53 Correct 261 ms 5628 KB Output is correct
54 Correct 287 ms 5624 KB Output is correct
55 Correct 277 ms 5712 KB Output is correct
56 Correct 31 ms 860 KB Output is correct
57 Correct 32 ms 856 KB Output is correct
58 Correct 355 ms 4428 KB Output is correct
59 Correct 331 ms 4436 KB Output is correct
60 Correct 270 ms 4456 KB Output is correct
61 Correct 351 ms 4440 KB Output is correct
62 Correct 323 ms 4456 KB Output is correct
63 Correct 273 ms 4440 KB Output is correct
64 Execution timed out 1038 ms 4944 KB Time limit exceeded
65 Halted 0 ms 0 KB -