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Submission #659495

# Submission time Handle Problem Language Result Execution time Memory
659495 2022-11-18T09:28:23 Z Ronin13 Valley (BOI19_valley) C++14
100 / 100
 393 ms 40244 KB 
#include <bits/stdc++.h>
#define ll long long
#define f first
#define s second
#define pii pair<int,int>
#define pll pair<ll,ll>
#define pb push_back
#define epb emplace_back
#define ull unsigned ll
using namespace std;

const int nmax = 2e5 + 1;
vector <vector <ll> > t(nmax);
vector <vector <pii> > g(nmax);
vector <vector <int> > path(nmax);
vector <int> lead(nmax);
vector <int> p(nmax);
vector <int> sz(nmax);
vector <ll> d(nmax);
vector <ll> dp(nmax, 2e18);
vector <bool> shop(nmax);
vector <int> pp(nmax);
vector <int> in(nmax);
int timer = 1;
void dfs(int v, int e = 0){
    sz[v] = 1;
    p[v] = e;
    in[v] = timer++;
    for(auto x : g[v]){
        int to = x.f;
        ll len = x.s;
        if(to == e) continue;
        d[to] = d[v] + len;
        dfs(to, v);
        dp[v] = min(dp[v], dp[to] + len);
        sz[v] += sz[to];
    }
    if(shop[v]) dp[v] = 0;
}

void decompose(int v, int head, int e = 0){
    path[head].pb(v);
    pp[v] = path[head].size();
    lead[v] = head;
    for(auto x : g[v]){
        int to = x.f;
        if(to == e) continue;
        if(2 * sz[to] >= sz[v]) decompose(to, head, v);
        else decompose(to, to, v);
    }

}

void update(int v, int l, int r, int pos, int ind, ll val){
    if(pos > r || pos < l) return;
    if(l == r){
        t[ind][v] = min((ll)1e18, val);
        return;
    }
    int m = (l + r) / 2;
    update(2 * v, l, m, pos, ind, val);
    update(2 * v + 1, m + 1, r, pos, ind, val);
    t[ind][v] = min(t[ind][2 * v], t[ind][2 * v + 1]);
}

ll get(int v, int l, int r, int st, int fin, int ind){
    if(l > fin || r < st) return 1e18;
    if(l >= st && r <=  fin) {
        return t[ind][v];
    }
    int m = (l + r) / 2;
    return min(get(2 * v, l, m, st, fin, ind),
               get(2 * v + 1, m + 1, r, st, fin, ind));
}

void build(int n){
    for(int i = 1; i <= n; i++){
        t[i].resize(path[i].size() * 4);
    }
    for(int i= 1; i <= n; i++){
        update(1, 1, path[lead[i]].size(), pp[i], lead[i], -d[i] + dp[i]);
    }
}

ll lift(ll x, ll y){
    ll ans = 1e18;
    while(lead[x] != lead[y]){
        int v = lead[x];
        ans = min(ans, get(1, 1, path[v].size(), pp[v], pp[x], v));
        x = p[v];
    }
    int v = lead[x];
    ans = min(ans, get(1, 1,  path[v].size(), pp[y], pp[x], v));
    return ans;
}

int main(){
    #ifndef ONLINE_JUDGE
    //freopen("in.txt", "r", stdin);
    //freopen("out.txt", "w", stdout);
    #endif // ONLINE_JUDGE
    int n, s, q, e;
    cin >> n >> s >> q >> e;
    int edge[n];
    vector <pii> edges;
    for(int i = 1; i < n; i++){
        int u, v; cin >> u >> v;
        ll w; cin >> w;
        edges.pb({u, v});
        g[u].pb({v, w});
        g[v].pb({u, w});
    }
    for(int i = 1; i <= s; i++){
        int x; cin >> x;
        shop[x] = true;
    }
    dfs(e);
    decompose(e, e);

   /* for(int i = 1; i <= n; i++)
        cout << lead[i] << ' ';*/
    for(int i = 1; i < n; i++){
        int x = edges[i - 1].f, y = edges[i - 1].s;
        if(p[x] == y){
            edge[i] = x;
        }
        else edge[i] = y;
    }
    build(n);
    while(q--){
        int x, r; cin >> x >> r;
        int v = edge[x];
        if(in[v] > in[r] || (in[v] + sz[v] < in[r] + sz[r])) {
            cout << "escaped\n";
            continue;
        }
        ll D = lift(r, v);
        if(D == 1e18){
            cout << "oo\n";
            continue;
        }
        cout << D + d[r] << "\n";
    }
}

Subtask #1
9.0 / 9.0

# Verdict Execution time Memory Grader output
1 Correct 26 ms 21588 KB Output is correct
2 Correct 27 ms 21580 KB Output is correct
3 Correct 27 ms 21536 KB Output is correct
4 Correct 26 ms 21588 KB Output is correct

Subtask #2
27.0 / 27.0

# Verdict Execution time Memory Grader output
1 Correct 26 ms 21588 KB Output is correct
2 Correct 27 ms 21580 KB Output is correct
3 Correct 27 ms 21536 KB Output is correct
4 Correct 26 ms 21588 KB Output is correct
5 Correct 14 ms 21588 KB Output is correct
6 Correct 15 ms 21588 KB Output is correct
7 Correct 16 ms 21588 KB Output is correct
8 Correct 14 ms 21524 KB Output is correct
9 Correct 13 ms 21552 KB Output is correct
10 Correct 13 ms 21588 KB Output is correct
11 Correct 13 ms 21552 KB Output is correct
12 Correct 14 ms 21588 KB Output is correct
13 Correct 14 ms 21520 KB Output is correct
14 Correct 13 ms 21588 KB Output is correct

Subtask #3
23.0 / 23.0

# Verdict Execution time Memory Grader output
1 Correct 356 ms 38592 KB Output is correct
2 Correct 369 ms 36800 KB Output is correct
3 Correct 374 ms 35816 KB Output is correct
4 Correct 381 ms 37716 KB Output is correct
5 Correct 368 ms 37736 KB Output is correct
6 Correct 393 ms 39196 KB Output is correct

Subtask #4
41.0 / 41.0

# Verdict Execution time Memory Grader output
1 Correct 26 ms 21588 KB Output is correct
2 Correct 27 ms 21580 KB Output is correct
3 Correct 27 ms 21536 KB Output is correct
4 Correct 26 ms 21588 KB Output is correct
5 Correct 14 ms 21588 KB Output is correct
6 Correct 15 ms 21588 KB Output is correct
7 Correct 16 ms 21588 KB Output is correct
8 Correct 14 ms 21524 KB Output is correct
9 Correct 13 ms 21552 KB Output is correct
10 Correct 13 ms 21588 KB Output is correct
11 Correct 13 ms 21552 KB Output is correct
12 Correct 14 ms 21588 KB Output is correct
13 Correct 14 ms 21520 KB Output is correct
14 Correct 13 ms 21588 KB Output is correct
15 Correct 356 ms 38592 KB Output is correct
16 Correct 369 ms 36800 KB Output is correct
17 Correct 374 ms 35816 KB Output is correct
18 Correct 381 ms 37716 KB Output is correct
19 Correct 368 ms 37736 KB Output is correct
20 Correct 393 ms 39196 KB Output is correct
21 Correct 329 ms 38080 KB Output is correct
22 Correct 342 ms 36276 KB Output is correct
23 Correct 347 ms 35384 KB Output is correct
24 Correct 365 ms 37544 KB Output is correct
25 Correct 363 ms 40244 KB Output is correct
26 Correct 332 ms 38072 KB Output is correct
27 Correct 332 ms 36244 KB Output is correct
28 Correct 353 ms 35356 KB Output is correct
29 Correct 360 ms 36768 KB Output is correct
30 Correct 379 ms 37812 KB Output is correct
31 Correct 333 ms 38232 KB Output is correct
32 Correct 393 ms 36260 KB Output is correct
33 Correct 351 ms 35524 KB Output is correct
34 Correct 371 ms 37312 KB Output is correct
35 Correct 361 ms 40068 KB Output is correct
36 Correct 344 ms 38380 KB Output is correct