oj.uz

Submission #603406

# Submission time Handle Problem Language Result Execution time Memory
603406 2022-07-24T06:18:04 Z verngutz Aesthetic (NOI20_aesthetic) C++17
16 / 100
 1971 ms 177408 KB 
#include <bits/stdc++.h>
#define err(args...) {}
#ifdef DEBUG
#include "_debug.cpp"
#endif
using namespace std;
using ll = long long;
using ld = long double;
template <typename T> using lim = numeric_limits<T>;
template <typename T> istream& operator>>(istream& is, vector<T>& a) { for(T& x : a) { is >> x; } return is; }
template <typename X, typename Y> istream& operator>>(istream& is, pair<X, Y>& p) { return is >> p.first >> p.second; }
template <typename T> struct wedge {
    int i, u, v; T w, dw;
    wedge reverse() const { return {i, v, u, w, dw}; }
    friend ostream& operator<<(ostream& os, const wedge& e) {
        return os << "{u: " << e.u << ", v: " << e.v << ", w: " << e.w << "}";
    }
};
template <bool Directed, typename TEdge, bool Index> struct graph {
    using EType = TEdge;
    vector<TEdge> edges;
    vector<vector<int>> adj;
    graph(int n) : adj(n + Index) {}
    graph(int n, int m) : graph(n) { edges.reserve(m << not Directed); }
    TEdge& operator()(int e) { return edges[e]; }
    vector<int>& operator[](int u) { return adj[u]; }
    int size() { return adj.size() - Index; }
    void append(int u, const TEdge& e) {
        adj[u].push_back(edges.size());
        edges.push_back(e);
    }
    void add_edge(const TEdge& e) {
        append(e.u, e);
        if(not Directed) append(e.v, e.reverse());
    }
};
template <bool Directed, typename T, bool Index>
pair<vector<T>, vector<int>> sssp(graph<Directed, wedge<T>, Index>& g, const vector<int>& s) {
    vector<int> vis(g.adj.size()), p(g.adj.size(), -1);
    vector<T> d(g.adj.size(), lim<T>::max());
    priority_queue<pair<T, int>> pq;
    for(int u : s) {
        pq.push({d[u] = 0, u});
    }
    while(not pq.empty()) {
        int u = pq.top().second; pq.pop();
        if(not vis[u]) {
            vis[u] = true;
            for(int e : g[u]) {
                if(not vis[g(e).v] and d[g(e).v] > d[u] + g(e).w) {
                    pq.push({-(d[g(e).v] = d[u] + g(e).w), g(p[g(e).v] = e).v});
                }
            }
        }
    }
    return {move(d), move(p)};
}
template <typename TEdge, bool Index> pair<vector<int>, vector<vector<int>>> find_2eccs(graph<0, TEdge, Index>& g) {
    vector<int> vis(g.adj.size()), low(g.adj.size()), cut_edge(g.edges.size()), s;
    vector<vector<int>> _2eccs = {};
    int timer = 1;
    function<void(int, int)> dfs = [&](int u, int from) {
        vis[u] = low[u] = timer++;
        s.push_back(u);
        for(int e : g[u]) {
            if(not vis[g(e).v]) {
                dfs(g(e).v, e & ~1);
                if(vis[u] < low[g(e).v]) {
                    cut_edge[e] = cut_edge[e ^ 1] = true;
                    _2eccs.push_back(vector<int>());
                    do {
                        _2eccs.back().push_back(s.back()), s.pop_back();
                    } while(_2eccs.back().back() != g(e).v);
                }
                low[u] = min(low[u], low[g(e).v]);
            } else if((e & ~1) != from and vis[u] > vis[g(e).v]) {
                low[u] = min(low[u], vis[g(e).v]);
            }
        }
    };
    for(int u = Index; u < g.adj.size(); u++) if(not vis[u]) {
        dfs(u, -1);
        _2eccs.push_back(vector<int>());
        while(not s.empty()) {
            _2eccs.back().push_back(s.back()), s.pop_back();
        }
    }
    return {move(cut_edge), move(_2eccs)};
}
const int MAX_WI = 10;
int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(0);
    int n, m;
    cin >> n >> m;
    graph<0, wedge<ll>, 1> g(n, m);
    for(int i = 0; i < m; i++) {
        int u, v, w;
        cin >> u >> v >> w;
        g.add_edge({i, u, v, w});
    }
    ll max_dw = 0;
    for(int i = m - 1; i >= 0; i--) {
        g.edges[2 * i].dw = g.edges[2 * i + 1].dw = max_dw;
        max_dw = max(max_dw, g.edges[2 * i].w);
    }
    auto [ds, ps] = sssp(g, {1});
    auto [dt, pt] = sssp(g, {n});
    ll ans = ds[n];
    for(int delta = 1; delta <= MAX_WI; delta++) {
        graph<0, wedge<ll>, 1> sp_dag(n);
        for(auto [i, u, v, w, dw] : g.edges) {
            if(ds[u] + w + dt[v] < ds[n] + delta) {
                sp_dag.add_edge({i, u, v, w, dw});
            }
        }
        auto [cut_edge, _2eccs] = find_2eccs(sp_dag);
        bool increase = false;
        for(int ii = 0; ii < sp_dag.edges.size(); ii += 2) {
            auto [i, u, v, w, dw] = sp_dag.edges[ii];
            increase |= cut_edge[ii] and ds[u] + w + dw + dt[v] >= ds[n] + delta;
        }
        if(increase) {
            ans = ds[n] + delta;
        }
    }
    cout << ans << endl;
    return 0;
}

Compilation message

Aesthetic.cpp: In function 'int main()':
Aesthetic.cpp:119:28: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<wedge<long long int>, std::allocator<wedge<long long int> > >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  119 |         for(int ii = 0; ii < sp_dag.edges.size(); ii += 2) {
      |                         ~~~^~~~~~~~~~~~~~~~~~~~~
Aesthetic.cpp: In instantiation of 'std::pair<std::vector<int>, std::vector<std::vector<int> > > find_2eccs(graph<false, TEdge, Index>&) [with TEdge = wedge<long long int>; bool Index = true]':
Aesthetic.cpp:117:52:   required from here
Aesthetic.cpp:81:26: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::vector<int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   81 |     for(int u = Index; u < g.adj.size(); u++) if(not vis[u]) {
      |                        ~~^~~~~~~~~~~~~~

Subtask #1
0 / 5.0

# Verdict Execution time Memory Grader output
1 Incorrect 0 ms 340 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #2
0 / 8.0

# Verdict Execution time Memory Grader output
1 Incorrect 0 ms 340 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #3
0 / 7.0

# Verdict Execution time Memory Grader output
1 Incorrect 849 ms 78976 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #4
0 / 15.0

# Verdict Execution time Memory Grader output
1 Incorrect 845 ms 80424 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #5
16.0 / 16.0

# Verdict Execution time Memory Grader output
1 Correct 786 ms 66700 KB Output is correct
2 Correct 934 ms 154548 KB Output is correct
3 Correct 1838 ms 151268 KB Output is correct
4 Correct 1908 ms 151568 KB Output is correct
5 Correct 1887 ms 148804 KB Output is correct
6 Correct 1873 ms 150956 KB Output is correct
7 Correct 1863 ms 151068 KB Output is correct
8 Correct 1971 ms 148644 KB Output is correct
9 Correct 1907 ms 149124 KB Output is correct
10 Correct 1822 ms 149476 KB Output is correct
11 Correct 1765 ms 151676 KB Output is correct
12 Correct 664 ms 59208 KB Output is correct
13 Correct 1745 ms 152480 KB Output is correct
14 Correct 856 ms 173240 KB Output is correct
15 Correct 860 ms 177408 KB Output is correct
16 Correct 680 ms 62232 KB Output is correct
17 Correct 705 ms 66068 KB Output is correct
18 Correct 669 ms 61120 KB Output is correct
19 Correct 869 ms 155140 KB Output is correct
20 Correct 870 ms 155308 KB Output is correct
21 Correct 878 ms 155588 KB Output is correct
22 Correct 953 ms 155672 KB Output is correct

Subtask #6
0 / 22.0

# Verdict Execution time Memory Grader output
1 Correct 786 ms 66700 KB Output is correct
2 Correct 934 ms 154548 KB Output is correct
3 Correct 1838 ms 151268 KB Output is correct
4 Correct 1908 ms 151568 KB Output is correct
5 Correct 1887 ms 148804 KB Output is correct
6 Correct 1873 ms 150956 KB Output is correct
7 Correct 1863 ms 151068 KB Output is correct
8 Correct 1971 ms 148644 KB Output is correct
9 Correct 1907 ms 149124 KB Output is correct
10 Correct 1822 ms 149476 KB Output is correct
11 Correct 1765 ms 151676 KB Output is correct
12 Correct 664 ms 59208 KB Output is correct
13 Correct 1745 ms 152480 KB Output is correct
14 Correct 856 ms 173240 KB Output is correct
15 Correct 860 ms 177408 KB Output is correct
16 Correct 680 ms 62232 KB Output is correct
17 Correct 705 ms 66068 KB Output is correct
18 Correct 669 ms 61120 KB Output is correct
19 Correct 869 ms 155140 KB Output is correct
20 Correct 870 ms 155308 KB Output is correct
21 Correct 878 ms 155588 KB Output is correct
22 Correct 953 ms 155672 KB Output is correct
23 Incorrect 732 ms 60460 KB Output isn't correct
24 Halted 0 ms 0 KB -

Subtask #7
0 / 27.0

# Verdict Execution time Memory Grader output
1 Incorrect 0 ms 340 KB Output isn't correct
2 Halted 0 ms 0 KB -