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Submission #841313

# Submission time Handle Problem Language Result Execution time Memory
841313 2023-09-01T13:31:10 Z ArashJafariyan Valley (BOI19_valley) C++17
100 / 100
 180 ms 39004 KB 
#include <bits/stdc++.h>
using namespace std;
using ll = long long;

#define pb push_back

const int lg = 17 + 2, maxn = 1e5 + 4;
const ll inf = 1ll << 62, maxa = 1e15;

int n, s, q, e, low[maxn], anc[maxn][lg], cnt[maxn];
ll mn[maxn], d[maxn], cost[maxn][lg];
bitset<maxn> mark;
vector<array<int, 3>> g[maxn];

void dfs(int v, int par) {
    if (v != e) {
        anc[v][0] = par;
        for (int i = 1; i < lg; ++i) {
            int u = anc[v][i - 1];
            if (u != -1) {
                anc[v][i] = anc[u][i - 1];
            }
        }
    }

    if (mark[v]) {
        mn[v] = d[v];
    }

    for (auto [u, w, ind] : g[v]) {
        if (u != par) {
            cnt[u] = cnt[v] + 1;
            d[u] = d[v] + w;
            low[ind] = u;

            dfs(u, v);
    
            mn[v] = min(mn[v], mn[u]); 
        }
    } 
}

void calc(int v, int par) {
    cost[v][0] = mn[v] - (d[v] << 1);
    for (int i = 1; i < lg; ++i) {
        ll t = cost[v][i - 1];
        int u = anc[v][i - 1];
        if (u != -1) {
            t = min(t, cost[u][i - 1]);
        }
        cost[v][i] = t;
    }

    for (auto [u, w, ind] : g[v]) {
        if (u != par) {
            calc(u, v);
        }
    }
}

int up(int v, ll dis) {
    for (int i = 0; i < lg; ++i) {
        if (((1 << i) & dis) && v != -1) {
            v = anc[v][i];
        }
    }
    return v;
}

ll ans(int v, ll dis) {
    ll ret = inf;
    for (int i = 0; i < lg; ++i) {
        if (((1 << i) & dis) && v != -1) {
            ret = min(ret, cost[v][i]);
            v = anc[v][i];
        }
    }
    return ret;
}

int main() {
    ios::sync_with_stdio(0), cin.tie(0);

    cin >> n >> s >> q >> e;
    for (int i = 0; i < n - 1; ++i) {
        int v, u, w;
        cin >> v >> u >> w;
        
        --v, --u;
        g[v].pb({u, w, i});
        g[u].pb({v, w, i});
    }
    for (int i = 0; i < s; ++i) {
        int v;
        cin >> v;
        --v;
        mark[v] = 1;
    }
    
    for (int i = 0; i < n; ++i) {
        mn[i] = inf;
        for (int j = 0; j < lg; ++j) {
            anc[i][j] = -1;
            cost[i][j] = inf;
        }
    }
    
    --e;
    dfs(e, e);
    calc(e, e);

    for (int i = 0; i < q; ++i) {
        int f, v;
        cin >> f >> v;
        
        --f, --v;
        int u = low[f];
            
        ll dis = cnt[v] - cnt[u];

        if (dis < 0 || up(v, dis) != u) {
            cout << "escaped\n";
        }
        else {
            ll t = ans(v, dis + 1) + d[v];
            if (t > maxa) {
                cout << "oo\n";
            }
            else {
                cout << t << '\n';
            }
        }
    }

    return 0;
}

Subtask #1
9.0 / 9.0

# Verdict Execution time Memory Grader output
1 Correct 4 ms 2772 KB Output is correct
2 Correct 3 ms 2772 KB Output is correct
3 Correct 3 ms 2772 KB Output is correct
4 Correct 4 ms 2772 KB Output is correct

Subtask #2
27.0 / 27.0

# Verdict Execution time Memory Grader output
1 Correct 4 ms 2772 KB Output is correct
2 Correct 3 ms 2772 KB Output is correct
3 Correct 3 ms 2772 KB Output is correct
4 Correct 4 ms 2772 KB Output is correct
5 Correct 2 ms 3028 KB Output is correct
6 Correct 2 ms 3028 KB Output is correct
7 Correct 2 ms 3028 KB Output is correct
8 Correct 2 ms 3028 KB Output is correct
9 Correct 2 ms 3028 KB Output is correct
10 Correct 2 ms 3028 KB Output is correct
11 Correct 2 ms 3028 KB Output is correct
12 Correct 2 ms 3028 KB Output is correct
13 Correct 2 ms 3028 KB Output is correct
14 Correct 2 ms 3028 KB Output is correct

Subtask #3
23.0 / 23.0

# Verdict Execution time Memory Grader output
1 Correct 115 ms 36240 KB Output is correct
2 Correct 120 ms 35912 KB Output is correct
3 Correct 130 ms 35788 KB Output is correct
4 Correct 156 ms 37056 KB Output is correct
5 Correct 158 ms 37324 KB Output is correct
6 Correct 180 ms 38408 KB Output is correct

Subtask #4
41.0 / 41.0

# Verdict Execution time Memory Grader output
1 Correct 4 ms 2772 KB Output is correct
2 Correct 3 ms 2772 KB Output is correct
3 Correct 3 ms 2772 KB Output is correct
4 Correct 4 ms 2772 KB Output is correct
5 Correct 2 ms 3028 KB Output is correct
6 Correct 2 ms 3028 KB Output is correct
7 Correct 2 ms 3028 KB Output is correct
8 Correct 2 ms 3028 KB Output is correct
9 Correct 2 ms 3028 KB Output is correct
10 Correct 2 ms 3028 KB Output is correct
11 Correct 2 ms 3028 KB Output is correct
12 Correct 2 ms 3028 KB Output is correct
13 Correct 2 ms 3028 KB Output is correct
14 Correct 2 ms 3028 KB Output is correct
15 Correct 115 ms 36240 KB Output is correct
16 Correct 120 ms 35912 KB Output is correct
17 Correct 130 ms 35788 KB Output is correct
18 Correct 156 ms 37056 KB Output is correct
19 Correct 158 ms 37324 KB Output is correct
20 Correct 180 ms 38408 KB Output is correct
21 Correct 113 ms 35804 KB Output is correct
22 Correct 116 ms 35312 KB Output is correct
23 Correct 136 ms 35244 KB Output is correct
24 Correct 154 ms 36728 KB Output is correct
25 Correct 174 ms 39004 KB Output is correct
26 Correct 124 ms 35740 KB Output is correct
27 Correct 121 ms 35404 KB Output is correct
28 Correct 128 ms 35276 KB Output is correct
29 Correct 171 ms 36244 KB Output is correct
30 Correct 165 ms 37308 KB Output is correct
31 Correct 121 ms 35788 KB Output is correct
32 Correct 127 ms 35400 KB Output is correct
33 Correct 126 ms 35560 KB Output is correct
34 Correct 145 ms 36768 KB Output is correct
35 Correct 159 ms 38792 KB Output is correct
36 Correct 132 ms 37164 KB Output is correct