oj.uz

Submission #1096417

# Submission time Handle Problem Language Result Execution time Memory
1096417 2024-10-04T12:16:54 Z snowmel Valley (BOI19_valley) C++17
59 / 100
 110 ms 21748 KB 
#include <bits/stdc++.h>
using namespace std;
using ll = long long;
int N, S, Q, H, C;
vector<pair<int,int>> QRS;
vector<tuple<int,int,ll>> edges;
vector<int> villages;
namespace sub12 {
vector<vector<int>> adj;
vector<int> is_village;
bool check() {
    return 1ll * N * Q <= int(1e6);
}
array<ll,3> dfs(int u, int p = -1) {
    array<ll,3> res;
    res[0] = res[1] = 0;
    res[2] = 1e18;
    if(u == H) res[0] = 1;
    if(is_village[u]) {
        res[1] = 1;
        res[2] = 0;
    }
    for(auto&& eid : adj[u]) {
        auto [ut, vt, w] = edges[eid];
        auto v = (ut != u ? ut : vt);
        if(v == p || w == -1) continue;
        auto t = dfs(v, u);
        res[0] |= t[0];
        res[1] |= t[1];
        if(t[1]) res[2] = min(res[2], t[2] + w);
    }
    return res;
}
void solve() {
    adj.assign(N, vector<int>());
    is_village.assign(N, 0);
    for(int i = 0; auto&& [x, y, z] : edges) {
        adj[x].emplace_back(i);
        adj[y].emplace_back(i);
        ++i;
    }
    for(auto&& v : villages) is_village[v] = 1;
    for(auto&& [x, y] : QRS) {
        auto t = get<2>(edges[x]);
        get<2>(edges[x]) = -1;
        auto tt = dfs(y);
        get<2>(edges[x]) = t;
        if(tt[0]) {
            cout << "escaped\n";
        } else if(tt[1]) {
            cout << tt[2] << "\n";
        } else {
            cout << "oo\n";
        }
    }
}
};
template<typename Monoid>
struct SegTree {
    using MX = Monoid;
    using X = typename Monoid::X;
    int n, log, size;
    vector<X> dat;
    SegTree() {}
    template<typename F>
    void build(int _n, F f) {
        n = _n, log = 0;
        while((1 << log) < n) ++log;
        size = 1 << log;
        dat.assign(size << 1, MX::unit());
        for(int i = 0; i < n; ++i) dat[i] = f(i);
        for(int i = size - 1; i >= 1; --i) update(i);
    }
    void set(int k, const X& x) {
        assert(0 <= k && k < n);
        dat[k += size] = x;
        while(k >>= 1) update(k);
    }
    X prod(int l, int r) {
        assert(0 <= l && l <= r && r <= n);
        l += size, r += size;
        X vl = MX::unit(), vr = MX::unit();
        while(l < r) {
            if(l & 1) vl = MX::op(vl, dat[l++]);
            if(r & 1) vr = MX::op(dat[--r], vr);
            l >>= 1, r >>= 1;
        }
        return MX::op(vl, vr);
    }
    void update(int k) { dat[k] = MX::op(dat[k << 1], dat[k << 1 | 1]); }
};
struct Monoid_1 {
    using X = int;
    using value_type = X;
    static constexpr X op(const X& x, const X& y) noexcept { return x | y; }
    static constexpr X unit() noexcept { return 0; }
};
namespace sub3 {
bool check() {
    return S == N;
}
vector<vector<int>> adj;
vector<int> LID, RID, parent, V, head;
void dfs1(int u) {
    auto& sz = RID;
    sz[u] = 1;
    int mx = 0;
    for(auto& eid : adj[u]) {
        auto&& [ut, vt, w] = edges[eid];
        int v = (u != ut ? ut : vt);
        if(v == parent[u]) continue;
        parent[v] = u;
        dfs1(v);
        sz[u] += sz[v];
        if(sz[v] > mx) {
            mx = sz[v];
            swap(eid, adj[u][0]);
        }
    }
}
void dfs2(int u, int& times) {
    LID[u] = times++;
    RID[u] += LID[u];
    V[LID[u]] = u;
    bool heavy = true;
    for(auto&& eid : adj[u]) {
        auto&& [ut, vt, w] = edges[eid];
        int v = (u != ut ? ut : vt);
        if(v == parent[u]) continue;
        head[v] = (heavy ? head[u] : v);
        heavy = false;
        dfs2(v, times);
    }
}
int LCA(int u, int v) {
    for(int i = 25; i--; ) {
        if(LID[u] > LID[v]) swap(u, v);
        if(head[u] == head[v]) return u;
        v = parent[head[v]];
    }
    assert(false);
}
vector<pair<int,int>> get_path_decomposition(int u, int v, bool edge = 0) {
    vector<pair<int,int>> up, down;
    while(true) {
        if(head[u] == head[v]) break;
        if(LID[u] < LID[v]) {
            down.emplace_back(LID[head[v]], LID[v]);
            v = parent[head[v]];
        } else {
            up.emplace_back(LID[u], LID[head[u]]);
            u = parent[head[u]];
        }
    }
    if(LID[u] < LID[v]) down.emplace_back(LID[u] + edge, LID[v]);
    else if(LID[v] + edge <= LID[u]) up.emplace_back(LID[u], LID[v] + edge);
    up.insert(up.end(), down.rbegin(), down.rend());
    return up;
}
void solve() {
    adj.assign(N, vector<int>());
    LID.resize(N);
    RID.resize(N);
    parent.resize(N);
    V.resize(N);
    head.resize(N);
    for(int i = 0; auto&& [x, y, z] : edges) {
        adj[x].emplace_back(i);
        adj[y].emplace_back(i);
        ++i;
    }
    parent[0] = -1;
    dfs1(0);
    int times = 0;
    head[0] = 0;
    dfs2(0, times);
    SegTree<Monoid_1> seg;
    seg.build(N, [](const int& i) { return 0; });
    for(auto&& [x, y] : QRS) {
        auto [ut, vt, w] = edges[x];
        if(LID[ut] < LID[vt]) swap(ut, vt);
        seg.set(LID[ut], 1);
        //cout << LID[ut] << "\n";
        bool fl = true;
        if(LCA(H, y) != ut) {
            auto pd = get_path_decomposition(H, y);
            for(auto&& [l, r] : pd) {
                if(l > r) swap(l, r);
                //cout << l << " " << r << "\n";
                if(seg.prod(l, r + 1) != 0) {
                    fl = false;
                    break;
                }
            }
        }
        seg.set(LID[ut], 0);
        if(fl) {
            cout << "escaped\n";
        } else {
            cout << "0\n";
        }
    }
}
};
void solve() {
    cin >> N >> S >> Q >> H;
    --H;
    edges.resize(N - 1);
    QRS.resize(Q);
    villages.resize(S);
    for(auto& [u, v, w] : edges) {
        cin >> u >> v >> w;
        --u, --v;
    }
    for(auto& v : villages) {
        cin >> v;
        --v;
    }
    for(auto& [x, y] : QRS) {
        cin >> x >> y;
        --x, --y;
    }
    if(sub12::check()) return sub12::solve();
    if(sub3::check()) return sub3::solve();
    sub3::solve();
}
int main() {
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    int t = 1;
    while(t--) solve();
}

Compilation message

valley.cpp: In function 'void sub12::solve()':
valley.cpp:37:20: warning: range-based 'for' loops with initializer only available with '-std=c++2a' or '-std=gnu++2a'
   37 |     for(int i = 0; auto&& [x, y, z] : edges) {
      |                    ^~~~
valley.cpp: In function 'void sub3::solve()':
valley.cpp:167:20: warning: range-based 'for' loops with initializer only available with '-std=c++2a' or '-std=gnu++2a'
  167 |     for(int i = 0; auto&& [x, y, z] : edges) {
      |                    ^~~~

Subtask #1
9.0 / 9.0

# Verdict Execution time Memory Grader output
1 Correct 9 ms 604 KB Output is correct
2 Correct 9 ms 592 KB Output is correct
3 Correct 9 ms 596 KB Output is correct
4 Correct 9 ms 604 KB Output is correct

Subtask #2
27.0 / 27.0

# Verdict Execution time Memory Grader output
1 Correct 9 ms 604 KB Output is correct
2 Correct 9 ms 592 KB Output is correct
3 Correct 9 ms 596 KB Output is correct
4 Correct 9 ms 604 KB Output is correct
5 Correct 6 ms 348 KB Output is correct
6 Correct 7 ms 568 KB Output is correct
7 Correct 14 ms 600 KB Output is correct
8 Correct 5 ms 344 KB Output is correct
9 Correct 7 ms 348 KB Output is correct
10 Correct 16 ms 600 KB Output is correct
11 Correct 6 ms 348 KB Output is correct
12 Correct 7 ms 344 KB Output is correct
13 Correct 14 ms 604 KB Output is correct
14 Correct 12 ms 604 KB Output is correct

Subtask #3
23.0 / 23.0

# Verdict Execution time Memory Grader output
1 Correct 96 ms 15700 KB Output is correct
2 Correct 99 ms 15952 KB Output is correct
3 Correct 110 ms 15952 KB Output is correct
4 Correct 96 ms 17732 KB Output is correct
5 Correct 90 ms 17744 KB Output is correct
6 Correct 90 ms 21748 KB Output is correct

Subtask #4
0 / 41.0

# Verdict Execution time Memory Grader output
1 Correct 9 ms 604 KB Output is correct
2 Correct 9 ms 592 KB Output is correct
3 Correct 9 ms 596 KB Output is correct
4 Correct 9 ms 604 KB Output is correct
5 Correct 6 ms 348 KB Output is correct
6 Correct 7 ms 568 KB Output is correct
7 Correct 14 ms 600 KB Output is correct
8 Correct 5 ms 344 KB Output is correct
9 Correct 7 ms 348 KB Output is correct
10 Correct 16 ms 600 KB Output is correct
11 Correct 6 ms 348 KB Output is correct
12 Correct 7 ms 344 KB Output is correct
13 Correct 14 ms 604 KB Output is correct
14 Correct 12 ms 604 KB Output is correct
15 Correct 96 ms 15700 KB Output is correct
16 Correct 99 ms 15952 KB Output is correct
17 Correct 110 ms 15952 KB Output is correct
18 Correct 96 ms 17732 KB Output is correct
19 Correct 90 ms 17744 KB Output is correct
20 Correct 90 ms 21748 KB Output is correct
21 Incorrect 88 ms 15184 KB Output isn't correct
22 Halted 0 ms 0 KB -