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Submission #961041

# Submission time Handle Problem Language Result Execution time Memory
961041 2024-04-11T12:35:22 Z bebra Cat Exercise (JOI23_ho_t4) C++17
31 / 100
 1551 ms 2496 KB 
#include <bits/stdc++.h>
using namespace std;

#define dbg(x) cerr << #x << ": " << x << endl;




const int MAX_N = 6000 + 5;
const int MAX_K = 13;
vector<int> g[MAX_N];
bool used[MAX_N];

int tin[MAX_N];
int tout[MAX_N];
int timer = 0;

int binup[MAX_K][MAX_N];
int max_vertex[MAX_K][MAX_N];

int depth[MAX_N];

void dfs(int v) {
    tin[v] = timer++;
    for (auto u : g[v]) {
        g[u].erase(find(g[u].begin(), g[u].end(), v));

        binup[0][u] = v;
        max_vertex[0][v] = v;
        depth[u] = depth[v] + 1;
        dfs(u);
    }
    tout[v] = timer++;
}

bool is_parent(int p, int v) {
    return (tin[p] <= tin[v] && tout[v] <= tout[p]);
}

int lca(int u, int v) {
    if (is_parent(u, v)) return u;
    if (is_parent(v, u)) return v;

    for (int k = MAX_K - 1; k >= 0; --k) {
        if (!is_parent(binup[k][v], u)) {
            v = binup[k][v];
        }
    }
    return binup[0][v];
}

int dist(int u, int v) {
    return depth[u] + depth[v] - 2 * depth[lca(u, v)];
}

int max_v(int u, int v) {
    if (is_parent(u, v)) {
        v = binup[0][v];
        int w = depth[v] - depth[u];
        int res = -1;
        for (int k = MAX_K - 1; k >= 0; --k) {
            if (w & (1 << k)) {
                res = max(res, max_vertex[k][v]);
                v = binup[k][v];
            }
        }
        return res;
    } else if (is_parent(v, u)) {
        u = binup[0][u];
        int w = depth[u] - depth[v];
        int res = -1;
        for (int k = MAX_K - 1; k >= 0; --k) {
            if (w & (1 << k)) {
                res = max(res, max_vertex[k][u]);
                u = binup[k][u];
            }
        }
        return res;
    } else {
        v = binup[0][v];
        u = binup[0][u];

        int c = lca(u, v);
        int w1 = depth[u] - depth[c];
        int res1 = -1;
        for (int k = MAX_K - 1; k >= 0; --k) {
            if (w1 & (1 << k)) {
                res1 = max(res1, max_vertex[k][u]);
                u = binup[k][u];
            }
        }
        int w2 = depth[v] - depth[c];
        int res2 = -1;
        for (int k = MAX_K - 1; k >= 0; --k) {
            if (w2 & (1 << k)) {
                res2 = max(res2, max_vertex[k][v]);
                v = binup[k][v];
            }
        }
        return max(c, max(res1, res2));
    }
}

int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);

    int n;
    cin >> n;
    vector<int> p(n);
    for (auto& x : p) {
        cin >> x;
        --x;
    }

    for (int i = 0; i < n - 1; ++i) {
        int u, v;
        cin >> u >> v;
        --u, --v;

        u = p[u];
        v = p[v];

        g[u].push_back(v);
        g[v].push_back(u);
    }

    dfs(0);

    for (int k = 1; k < MAX_K; ++k) {
        for (int v = 0; v < n; ++v) {
            binup[k][v] = binup[k - 1][binup[k - 1][v]];
            max_vertex[k][v] = max(max_vertex[k - 1][v], max_vertex[k - 1][binup[k - 1][v]]);
        }
    }

    vector<int64_t> dp(n, -1e9);
    dp.back() = 0;
    int64_t res = 0;
    for (int v = n - 2; v >= 0; --v) {
        for (int u = v + 1; u < n; ++u) {
            // dbg(u);
            // dbg(v);
            // dbg(max_v(u, v));
            if (max_v(u, v) < min(u, v)) {
                dp[v] = max(dp[v], dp[u] + dist(u, v));
            }
        }
        res = max(res, dp[v]);
        // cerr << endl;
        // dbg(v);
        // dbg(dp[v]);
        // cerr << endl;
    }

    // dbg(max_v(2, 0));

    cout << res << '\n';
    
    return 0;
}


/*
16
16 8 7 9 1 5 3 13 11 15 12 10 2 4 14 6
1 2
2 3
3 4
4 5
5 6
6 7
7 8
8 9
9 10
10 11
11 12
12 13
13 14
14 15
15 16

22

*/

Subtask #1
7.0 / 7.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 600 KB Output is correct
2 Correct 1 ms 604 KB Output is correct
3 Correct 0 ms 604 KB Output is correct
4 Correct 0 ms 604 KB Output is correct
5 Correct 1 ms 604 KB Output is correct
6 Correct 1 ms 604 KB Output is correct
7 Correct 1 ms 604 KB Output is correct
8 Correct 1 ms 600 KB Output is correct
9 Correct 1 ms 600 KB Output is correct
10 Correct 1 ms 604 KB Output is correct

Subtask #2
7.0 / 7.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 600 KB Output is correct
2 Correct 1 ms 604 KB Output is correct
3 Correct 0 ms 604 KB Output is correct
4 Correct 0 ms 604 KB Output is correct
5 Correct 1 ms 604 KB Output is correct
6 Correct 1 ms 604 KB Output is correct
7 Correct 1 ms 604 KB Output is correct
8 Correct 1 ms 600 KB Output is correct
9 Correct 1 ms 600 KB Output is correct
10 Correct 1 ms 604 KB Output is correct
11 Correct 4 ms 604 KB Output is correct
12 Correct 3 ms 604 KB Output is correct
13 Correct 2 ms 784 KB Output is correct
14 Correct 5 ms 776 KB Output is correct
15 Correct 4 ms 604 KB Output is correct
16 Correct 4 ms 600 KB Output is correct
17 Correct 5 ms 604 KB Output is correct

Subtask #3
7.0 / 7.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 600 KB Output is correct
2 Correct 1 ms 604 KB Output is correct
3 Correct 0 ms 604 KB Output is correct
4 Correct 0 ms 604 KB Output is correct
5 Correct 1 ms 604 KB Output is correct
6 Correct 1 ms 604 KB Output is correct
7 Correct 1 ms 604 KB Output is correct
8 Correct 1 ms 600 KB Output is correct
9 Correct 1 ms 600 KB Output is correct
10 Correct 1 ms 604 KB Output is correct
11 Correct 4 ms 604 KB Output is correct
12 Correct 3 ms 604 KB Output is correct
13 Correct 2 ms 784 KB Output is correct
14 Correct 5 ms 776 KB Output is correct
15 Correct 4 ms 604 KB Output is correct
16 Correct 4 ms 600 KB Output is correct
17 Correct 5 ms 604 KB Output is correct
18 Correct 965 ms 1664 KB Output is correct
19 Correct 559 ms 1860 KB Output is correct
20 Correct 568 ms 1884 KB Output is correct
21 Correct 1373 ms 1876 KB Output is correct
22 Correct 940 ms 1832 KB Output is correct
23 Correct 1320 ms 1720 KB Output is correct
24 Correct 1016 ms 1828 KB Output is correct

Subtask #4
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 600 KB Output is correct
2 Correct 1 ms 604 KB Output is correct
3 Correct 0 ms 604 KB Output is correct
4 Correct 0 ms 604 KB Output is correct
5 Correct 1 ms 604 KB Output is correct
6 Correct 1 ms 604 KB Output is correct
7 Correct 1 ms 604 KB Output is correct
8 Correct 1 ms 600 KB Output is correct
9 Correct 1 ms 600 KB Output is correct
10 Correct 1 ms 604 KB Output is correct
11 Correct 4 ms 604 KB Output is correct
12 Correct 3 ms 604 KB Output is correct
13 Correct 2 ms 784 KB Output is correct
14 Correct 5 ms 776 KB Output is correct
15 Correct 4 ms 604 KB Output is correct
16 Correct 4 ms 600 KB Output is correct
17 Correct 5 ms 604 KB Output is correct
18 Correct 965 ms 1664 KB Output is correct
19 Correct 559 ms 1860 KB Output is correct
20 Correct 568 ms 1884 KB Output is correct
21 Correct 1373 ms 1876 KB Output is correct
22 Correct 940 ms 1832 KB Output is correct
23 Correct 1320 ms 1720 KB Output is correct
24 Correct 1016 ms 1828 KB Output is correct
25 Correct 0 ms 604 KB Output is correct
26 Correct 839 ms 1744 KB Output is correct
27 Correct 863 ms 1628 KB Output is correct
28 Correct 852 ms 1744 KB Output is correct
29 Correct 819 ms 1748 KB Output is correct
30 Correct 1453 ms 1480 KB Output is correct
31 Correct 1541 ms 1480 KB Output is correct
32 Correct 1551 ms 1480 KB Output is correct
33 Correct 1529 ms 1476 KB Output is correct

Subtask #5
0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 600 KB Output is correct
2 Correct 1 ms 604 KB Output is correct
3 Correct 0 ms 604 KB Output is correct
4 Correct 0 ms 604 KB Output is correct
5 Correct 1 ms 604 KB Output is correct
6 Correct 1 ms 604 KB Output is correct
7 Correct 1 ms 604 KB Output is correct
8 Correct 1 ms 600 KB Output is correct
9 Correct 1 ms 600 KB Output is correct
10 Correct 1 ms 604 KB Output is correct
11 Correct 4 ms 604 KB Output is correct
12 Correct 3 ms 604 KB Output is correct
13 Correct 2 ms 784 KB Output is correct
14 Correct 5 ms 776 KB Output is correct
15 Correct 4 ms 604 KB Output is correct
16 Correct 4 ms 600 KB Output is correct
17 Correct 5 ms 604 KB Output is correct
18 Correct 965 ms 1664 KB Output is correct
19 Correct 559 ms 1860 KB Output is correct
20 Correct 568 ms 1884 KB Output is correct
21 Correct 1373 ms 1876 KB Output is correct
22 Correct 940 ms 1832 KB Output is correct
23 Correct 1320 ms 1720 KB Output is correct
24 Correct 1016 ms 1828 KB Output is correct
25 Runtime error 13 ms 2392 KB Execution killed with signal 11
26 Halted 0 ms 0 KB -

Subtask #6
0 / 23.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 604 KB Output is correct
2 Correct 2 ms 604 KB Output is correct
3 Runtime error 15 ms 2496 KB Execution killed with signal 11
4 Halted 0 ms 0 KB -

Subtask #7
0 / 26.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 600 KB Output is correct
2 Correct 1 ms 604 KB Output is correct
3 Correct 0 ms 604 KB Output is correct
4 Correct 0 ms 604 KB Output is correct
5 Correct 1 ms 604 KB Output is correct
6 Correct 1 ms 604 KB Output is correct
7 Correct 1 ms 604 KB Output is correct
8 Correct 1 ms 600 KB Output is correct
9 Correct 1 ms 600 KB Output is correct
10 Correct 1 ms 604 KB Output is correct
11 Correct 4 ms 604 KB Output is correct
12 Correct 3 ms 604 KB Output is correct
13 Correct 2 ms 784 KB Output is correct
14 Correct 5 ms 776 KB Output is correct
15 Correct 4 ms 604 KB Output is correct
16 Correct 4 ms 600 KB Output is correct
17 Correct 5 ms 604 KB Output is correct
18 Correct 965 ms 1664 KB Output is correct
19 Correct 559 ms 1860 KB Output is correct
20 Correct 568 ms 1884 KB Output is correct
21 Correct 1373 ms 1876 KB Output is correct
22 Correct 940 ms 1832 KB Output is correct
23 Correct 1320 ms 1720 KB Output is correct
24 Correct 1016 ms 1828 KB Output is correct
25 Correct 0 ms 604 KB Output is correct
26 Correct 839 ms 1744 KB Output is correct
27 Correct 863 ms 1628 KB Output is correct
28 Correct 852 ms 1744 KB Output is correct
29 Correct 819 ms 1748 KB Output is correct
30 Correct 1453 ms 1480 KB Output is correct
31 Correct 1541 ms 1480 KB Output is correct
32 Correct 1551 ms 1480 KB Output is correct
33 Correct 1529 ms 1476 KB Output is correct
34 Runtime error 13 ms 2392 KB Execution killed with signal 11
35 Halted 0 ms 0 KB -