oj.uz

Submission #213537

# Submission time Handle Problem Language Result Execution time Memory
213537 2020-03-26T05:24:30 Z usachevd0 Valley (BOI19_valley) C++14
36 / 100
 3000 ms 18940 KB 
#include <bits/stdc++.h>

using namespace std;

#define fi first
#define se second
#define mp make_pair
#define pb push_back
#define all(a) (a).begin(), (a).end()

typedef long long ll;
typedef unsigned long long ull;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
typedef long double ld;

template<typename T1, typename T2> bool chkmin(T1 &x, T2 y) { return y < x ? (x = y, true) : false; }
template<typename T1, typename T2> bool chkmax(T1 &x, T2 y) { return y > x ? (x = y, true) : false; }

void debug_out()
{
    cerr << endl;
}

template<typename T1, typename... T2> void debug_out(T1 A, T2... B)
{
    cerr << ' ' << A;
    debug_out(B...);
}

#ifdef DEBUG
    #define debug(...) cerr << "[" << #__VA_ARGS__ << "]:", debug_out(__VA_ARGS__)
#else
    #define debug(...) 42
#endif

const int maxN = 100005;
const ll INF64 = 1e18;
int N, S, Q, root;
vector< pair<int, ll> > G[maxN];
bool good[maxN];
int par[maxN];
int tin[maxN], tout[maxN];

ll ans[maxN];
vector<pii> qvtx[maxN];

int timer;
void dfs0(int v, int p = -1)
{
    par[v] = p;
    tin[v] = timer++;
    for (auto e : G[v])
    {
        int u = e.fi;
        if (u != p)
        {
            dfs0(u, v);
        }
    }
    tout[v] = timer - 1;
}

bool upper(int a, int b)
{
    return tin[a] <= tin[b] && tout[b] <= tout[a];
}

mt19937 rng(time(0));
struct Node
{
    int y;
    int v;
    ll m, down_m;
    ll s, down_s;
    int sz;
    Node *l, *r;

    Node() {}
    Node(int _v)
    {
        y = rng();
        v = _v;
        sz = 1;
        m = down_m = INF64;
        s = down_s = 0;
        down_s = 0;
        l = r = 0;
    }
};

int sz(Node *&t)
{
    return t ? t->sz : 0;
}

void upd(Node *&t)
{
    if (t)
    {
        t->sz = sz(t->l) + 1 + sz(t->r);
    }
}

void apply_m(Node *&t, ll x)
{
    if (t)
    {
        chkmin(t->m, x);
        chkmin(t->down_m, x);
    }
}

void apply_s(Node *&t, ll x)
{
    if (t)
    {
        t->s += x;
        t->down_s += x;
    }
}

void push(Node *&t)
{
    if (!t) return;
    if (t->down_s)
    {
        apply_s(t->l, t->down_s);
        apply_s(t->r, t->down_s);
        t->down_s = 0;
    }
    if (t->down_m < INF64)
    {
        apply_m(t->l, t->down_m);
        apply_m(t->r, t->down_m);
        t->down_m = INF64;
    }
}

Node* merge(Node *a, Node *b)
{
    if (!a) return b;
    if (!b) return a;
    if (a->y > b->y)
    {
        push(a);
        a->r = merge(a->r, b);
        upd(a);
        return a;
    }
    else
    {
        push(b);
        b->l = merge(a, b->l);
        upd(b);
        return b;
    }
}

ll gt(Node *t, int k)
{
    if (!t) return INF64;
    int szl = sz(t->l);
    if (k == szl)
        return t->m + t->s;
    push(t);
    if (k < szl)
        return gt(t->l, k);
    else
        return gt(t->r, k - szl - 1);
}

void Tdebug(Node *t)
{
    if (t)
    {
        push(t);
        Tdebug(t->l);
        cout << t->v << '|' << t->m + t->s << ' ';
        Tdebug(t->r);
    }
}

pair<Node*, ll> dfs1(int v, int p = -1)
{
    Node* T = new Node(v);
    ll closest_down = INF64;
    if (good[v])
    {
        apply_m(T, 0);
        closest_down = 0;
    }
    for (auto e : G[v])
    {
        int u = e.fi;
        ll c = e.se;
        if (u != p)
        {
            auto res = dfs1(u, v);
            auto Q = res.fi;
            ll cd = res.se + c;
            apply_m(T, cd);
            apply_s(Q, c);
            apply_m(Q, closest_down);
            T = merge(T, Q);
            chkmin(closest_down, cd);
        }
    }
    for (pii q : qvtx[v])
    {
        int u = q.fi;
        int idx = q.se;
        int pos = tin[u] - tin[v];
        ans[idx] = gt(T, pos);
    }
//    debug(v, closest_down); Tdebug(T); cout << endl;
    return {T, closest_down};
}

ll dist[maxN];
ll dijk(int v, int ban)
{
    fill(dist, dist + N + 1, INF64);
    dist[v] = 0;
    multiset< pair<ll, int> > q;
    q.insert(mp(0, v));
    ll ans = INF64;
    while (!q.empty())
    {
        int v = q.begin()->se;
        ll _d = q.begin()->fi;
        q.erase(q.begin());

        if (_d != dist[v]) continue;
        if (good[v]) chkmin(ans, dist[v]);

        for (auto e : G[v])
        {
            int u = e.fi;
            ll c = e.se;
            if (u != ban)
            {
                if (chkmin(dist[u], dist[v] + c))
                {
                    q.insert(mp(dist[u], u));
                }
            }
        }
    }
    return ans;
}

signed main()
{
#ifdef DEBUG
    freopen("in", "r", stdin);
#endif
    ios::sync_with_stdio(0);
    cin.tie(0);

    cin >> N >> S >> Q >> root;
    pii edges[N - 1];
    for (int i = 0; i < N - 1; ++i)
    {
        int a, b;
        ll c;
        cin >> a >> b >> c;
        G[a].emplace_back(b, c);
        G[b].emplace_back(a, c);
        edges[i] = {a, b};
    }
    while (S--)
    {
        int v;
        cin >> v;
        good[v] = true;
    }
    dfs0(root);
    fill(ans, ans + Q, INF64);
    for (int i = 0; i < Q; ++i)
    {
        int ei, u;
        cin >> ei >> u;
        --ei;
        int v = edges[ei].fi == par[edges[ei].se] ? edges[ei].se : edges[ei].fi;
        if (!upper(v, u))
        {
            cout << "escaped\n";
            continue;
        }
        ll ans = dijk(u, par[v]);
        if (ans == INF64)
            cout << "oo\n";
        else
            cout << ans << '\n';
    }

    return 0;
}

Subtask #1
9.0 / 9.0

# Verdict Execution time Memory Grader output
1 Correct 24 ms 5120 KB Output is correct
2 Correct 19 ms 5376 KB Output is correct
3 Correct 17 ms 5376 KB Output is correct
4 Correct 20 ms 5120 KB Output is correct

Subtask #2
27.0 / 27.0

# Verdict Execution time Memory Grader output
1 Correct 24 ms 5120 KB Output is correct
2 Correct 19 ms 5376 KB Output is correct
3 Correct 17 ms 5376 KB Output is correct
4 Correct 20 ms 5120 KB Output is correct
5 Correct 8 ms 5248 KB Output is correct
6 Correct 8 ms 5248 KB Output is correct
7 Correct 15 ms 5120 KB Output is correct
8 Correct 8 ms 5248 KB Output is correct
9 Correct 9 ms 5248 KB Output is correct
10 Correct 39 ms 5248 KB Output is correct
11 Correct 9 ms 5248 KB Output is correct
12 Correct 11 ms 5248 KB Output is correct
13 Correct 14 ms 5248 KB Output is correct
14 Correct 37 ms 5248 KB Output is correct

Subtask #3
0 / 23.0

# Verdict Execution time Memory Grader output
1 Correct 2479 ms 16248 KB Output is correct
2 Correct 2709 ms 18940 KB Output is correct
3 Execution timed out 3100 ms 17528 KB Time limit exceeded
4 Halted 0 ms 0 KB -

Subtask #4
0 / 41.0

# Verdict Execution time Memory Grader output
1 Correct 24 ms 5120 KB Output is correct
2 Correct 19 ms 5376 KB Output is correct
3 Correct 17 ms 5376 KB Output is correct
4 Correct 20 ms 5120 KB Output is correct
5 Correct 8 ms 5248 KB Output is correct
6 Correct 8 ms 5248 KB Output is correct
7 Correct 15 ms 5120 KB Output is correct
8 Correct 8 ms 5248 KB Output is correct
9 Correct 9 ms 5248 KB Output is correct
10 Correct 39 ms 5248 KB Output is correct
11 Correct 9 ms 5248 KB Output is correct
12 Correct 11 ms 5248 KB Output is correct
13 Correct 14 ms 5248 KB Output is correct
14 Correct 37 ms 5248 KB Output is correct
15 Correct 2479 ms 16248 KB Output is correct
16 Correct 2709 ms 18940 KB Output is correct
17 Execution timed out 3100 ms 17528 KB Time limit exceeded
18 Halted 0 ms 0 KB -