oj.uz

Submission #672555

# Submission time Handle Problem Language Result Execution time Memory
672555 2022-12-16T15:33:21 Z _martynas Valley (BOI19_valley) C++11
100 / 100
 248 ms 50960 KB 
#include <bits/stdc++.h>

using namespace std;

using ll = long long;
using pii = pair<int, int>;
using pil = pair<int, ll>;
using pll = pair<ll, ll>;
using vi = vector<int>;
using vl = vector<ll>;

const int MOD = 1e9+7;

#define F first
#define S second
#define PB push_back
#define all(a) (a).begin(), (a).end()
#define rall(a) (a).rbegin(), (a).rend()

void FASTIO() {ios::sync_with_stdio(0); cin.tie(0); cout.tie(0); }

const int MXN = 1e5+5;
const int MXK = 16;
const ll INF = 1e15;

int n, s, q, e;
vector<tuple<int, int, ll>> E = {{}};
vector<pil> adj[MXN];
bool shop[MXN];
int BL[MXK][MXN];
ll BL_w[MXK][MXN];
ll BL_dp[MXK][MXN];
int H[MXN];
ll dp[MXN];

void dfs(int u, int p) {
    dp[u] = (shop[u] ? 0 : INF);
    for(auto edge : adj[u]) {
        int v = edge.F;
        if(v == p) continue;
        BL[0][v] = u;
        BL_w[0][v] = edge.S;
        H[v] = H[u]+1;
        dfs(v, u);
        dp[u] = min(dp[u], dp[v]+edge.S); // dp going down the subtree
    }
}

int main() {
    FASTIO();

    cin >> n >> s >> q >> e;
    for(int i = 0; i < n-1; i++) {
        int a, b, w; cin >> a >> b >> w;
        E.PB({a, b, w});
        adj[a].PB({b, w});
        adj[b].PB({a, w});
    }
    for(int i = 0; i < s; i++) {
        int j; cin >> j; shop[j] = true;
    }
    dfs(e, -1);
    BL[0][e] = e;
    for(int i = 1; i <= n; i++) {
        BL_dp[0][i] = min(dp[i], dp[BL[0][i]]+BL_w[0][i]);
    }
    for(int k = 1; k < MXK; k++) {
        for(int i = 1; i <= n; i++) {
            BL[k][i] = BL[k-1][BL[k-1][i]];
            BL_w[k][i] = BL_w[k-1][i]+BL_w[k-1][BL[k-1][i]];
            BL_dp[k][i] = min(BL_dp[k-1][i], BL_dp[k-1][BL[k-1][i]]+BL_w[k-1][i]);
        }
    }

    for(int qq = 0; qq < q; qq++) {
        int i, r; cin >> i >> r;
        // 1. binary lift to check if i-th edge is the one needed to take to reach the root
        // 2. if yes, check dp for minimal distance to shop(?)
        int u = H[get<0>(E[i])] > H[get<1>(E[i])] ? get<0>(E[i]) : get<1>(E[i]);
        if(H[r] < H[u]) {
            cout << "escaped\n";
            continue;
        }
        int v = r;
        ll ans = dp[r];
        ll curr = 0;
        for(int k = MXK-1; k >= 0; k--)
        while(H[BL[k][v]] >= H[u]) {
            ans = min(ans, BL_dp[k][v]+curr);
            curr += BL_w[k][v];
            v = BL[k][v];
        }
        if(u != v) {
            cout << "escaped\n";
            continue;
        }
        if(ans >= INF) {
            cout << "oo\n";
        }
        else {
            cout << ans << "\n";
        }
    }
    return 0;
}

/*



*/

Subtask #1
9.0 / 9.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 3028 KB Output is correct
2 Correct 4 ms 3028 KB Output is correct
3 Correct 4 ms 3068 KB Output is correct
4 Correct 4 ms 3028 KB Output is correct

Subtask #2
27.0 / 27.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 3028 KB Output is correct
2 Correct 4 ms 3028 KB Output is correct
3 Correct 4 ms 3068 KB Output is correct
4 Correct 4 ms 3028 KB Output is correct
5 Correct 2 ms 3328 KB Output is correct
6 Correct 2 ms 3284 KB Output is correct
7 Correct 3 ms 3284 KB Output is correct
8 Correct 2 ms 3284 KB Output is correct
9 Correct 3 ms 3284 KB Output is correct
10 Correct 4 ms 3284 KB Output is correct
11 Correct 4 ms 3284 KB Output is correct
12 Correct 3 ms 3284 KB Output is correct
13 Correct 4 ms 3332 KB Output is correct
14 Correct 3 ms 3324 KB Output is correct

Subtask #3
23.0 / 23.0

# Verdict Execution time Memory Grader output
1 Correct 113 ms 42552 KB Output is correct
2 Correct 127 ms 46184 KB Output is correct
3 Correct 154 ms 46492 KB Output is correct
4 Correct 187 ms 48328 KB Output is correct
5 Correct 190 ms 48488 KB Output is correct
6 Correct 248 ms 50616 KB Output is correct

Subtask #4
41.0 / 41.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 3028 KB Output is correct
2 Correct 4 ms 3028 KB Output is correct
3 Correct 4 ms 3068 KB Output is correct
4 Correct 4 ms 3028 KB Output is correct
5 Correct 2 ms 3328 KB Output is correct
6 Correct 2 ms 3284 KB Output is correct
7 Correct 3 ms 3284 KB Output is correct
8 Correct 2 ms 3284 KB Output is correct
9 Correct 3 ms 3284 KB Output is correct
10 Correct 4 ms 3284 KB Output is correct
11 Correct 4 ms 3284 KB Output is correct
12 Correct 3 ms 3284 KB Output is correct
13 Correct 4 ms 3332 KB Output is correct
14 Correct 3 ms 3324 KB Output is correct
15 Correct 113 ms 42552 KB Output is correct
16 Correct 127 ms 46184 KB Output is correct
17 Correct 154 ms 46492 KB Output is correct
18 Correct 187 ms 48328 KB Output is correct
19 Correct 190 ms 48488 KB Output is correct
20 Correct 248 ms 50616 KB Output is correct
21 Correct 106 ms 45816 KB Output is correct
22 Correct 123 ms 45664 KB Output is correct
23 Correct 144 ms 45848 KB Output is correct
24 Correct 168 ms 47968 KB Output is correct
25 Correct 215 ms 50960 KB Output is correct
26 Correct 112 ms 45900 KB Output is correct
27 Correct 133 ms 45696 KB Output is correct
28 Correct 151 ms 45896 KB Output is correct
29 Correct 151 ms 47352 KB Output is correct
30 Correct 242 ms 49160 KB Output is correct
31 Correct 131 ms 46000 KB Output is correct
32 Correct 152 ms 45764 KB Output is correct
33 Correct 149 ms 46032 KB Output is correct
34 Correct 156 ms 47972 KB Output is correct
35 Correct 210 ms 50840 KB Output is correct
36 Correct 162 ms 48008 KB Output is correct