oj.uz

Submission #978929

# Submission time Handle Problem Language Result Execution time Memory
978929 2024-05-10T03:42:58 Z asdfgrace Cat Exercise (JOI23_ho_t4) C++17
51 / 100
 2000 ms 63540 KB 
#include <bits/stdc++.h>
using namespace std;

#define dbg(x) x
#define prt(x) dbg(cerr << x)
#define pv(x) dbg(cerr << #x << " = " << x << '\n')
#define pv2(x) dbg(cerr << #x << " = " << x.first << ',' << x.second << '\n')
#define parr(x) dbg(prt(#x << " = { "); for (auto y : x) prt(y << ' '); prt("}\n");)
#define parr2(x) dbg(prt(#x << " = { "); for (auto [y, z] : x) prt(y << ',' << z << "  "); prt("}\n");)
#define parr2d(x) dbg(prt(#x << ":\n"); for (auto arr : x) {parr(arr);} prt('\n'));
#define parr2d2(x) dbg(prt(#x << ":\n"); for (auto arr : x) {parr2(arr);} prt('\n'));

const int lg = 20;

/*
tree
block nodes 1 by 1
on each move:
block a node
if you block the node with the cat on it
the cat moves to the MAXIMUM REACHABLE NODE
goal is make cat move as much as possible
note that whatever node you are at, you always have a number of subgraphs
you can break off into
pick the subgraph that yields you the best answer when you go to the max
value inside it
this is kind of the equivalent of blocking every other subgraph, then blocking
this node so you end up in the subgraph you chose
for (each subgraph)
dp[node] = max(dp[node], dp[subgraph] + dist(node, max in subgraph))
how do you get the max in subgraph though
same algo as centroid
if we can impl this in n^2, we get like 31 points
other special cases: path, binary tree
*/

int main() {
  ios::sync_with_stdio(0); cin.tie(0);
  int n;
  cin >> n;
  vector<int> p(n), at(n);
  for (int i = 0; i < n; i++) {
    cin >> p[i];
    p[i]--;
    at[p[i]] = i;
  }
  vector<vector<int>> edges(n);
  bool path = true;
  for (int i = 0; i < n - 1; i++) {
    int x, y;
    cin >> x >> y;
    x--; y--;
    if (y != x + 1) path = false;
    edges[x].push_back(y);
    edges[y].push_back(x);
  }
  if (path) {
    vector<vector<int>> rmq(n, vector<int>(lg, 0));
    for (int i = 0; i < n; i++) {
      rmq[i][0] = p[i];
    }
    for (int j = 1; j < lg; j++) {
      for (int i = 0; i < n - (1 << j) + 1; i++) {
        rmq[i][j] = max(rmq[i][j - 1], rmq[i + (1 << (j - 1))][j - 1]);
      }
    }
    function<int(int, int)> rmx = [&] (int l, int r) {
      int p2 = 31 - __builtin_clz(r - l + 1);
      return max(rmq[l][p2], rmq[r - (1 << p2) + 1][p2]);
    };
    vector<long long> best(n, 0);
    function<void(int, int, int)> dnc = [&] (int l, int r, int k) {
      if (k != l) {
        int kl = at[rmx(l, k - 1)];
        dnc(l, k - 1, kl);
        best[k] = max(best[k], best[kl] + k - kl);
      }
      if (k != r) {
        int kr = at[rmx(k + 1, r)];
        dnc(k + 1, r, kr);
        best[k] = max(best[k], best[kr] + kr - k);
      }
    };
    dnc(0, n - 1, at[n - 1]);
    cout << best[at[n - 1]] << '\n';
  } else {
    vector<int> dep(n, 0), tpar(n, 0);
    vector<long long> ans(n, 0);
    vector<bool> vis(n, false);
    function<void(int, int)> dfs_dep = [&] (int node, int par) {
      tpar[node] = par;
      for (auto next : edges[node]) {
        if (next == par) continue;
        dep[next] = dep[node] + 1;
        dfs_dep(next, node);
      }
    };
    dfs_dep(at[n - 1], at[n - 1]);
    function<int(int, int)> dist = [&] (int x, int y) {
      if (dep[x] > dep[y]) swap(x, y);
      int ret = 0;
      while (dep[y] > dep[x]) {
        y = tpar[y];
        ret++;
      }
      while (x != y) {
        x = tpar[x];
        y = tpar[y];
        ret += 2;
      }
      return ret;
    };
    function<int(int, int)> dfs_mx = [&] (int node, int par) {
      int ret = node;
      for (auto next : edges[node]) {
        if (next == par || vis[next]) continue;
        int x = dfs_mx(next, node);
        if (p[x] > p[ret]) {
          ret = x;
        }
      }
      return ret;
    };
    function<void(int, int)> dfs = [&] (int node, int par) {
      int mx = dfs_mx(node, node);
      vis[mx] = true;
      ans[mx] = ans[par] + dist(par, mx);
      for (auto next : edges[mx]) {
        if (!vis[next]) {
          dfs(next, mx);
        }
      }
    };
    dfs(at[n - 1], at[n - 1]);
    long long res = 0;
    for (int i = 0; i < n; i++) {
      res = max(res, ans[i]);
    }
    cout << res << '\n';
  }
}

Subtask #1
7.0 / 7.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 344 KB Output is correct
2 Correct 0 ms 348 KB Output is correct
3 Correct 0 ms 348 KB Output is correct
4 Correct 1 ms 460 KB Output is correct
5 Correct 1 ms 348 KB Output is correct
6 Correct 0 ms 460 KB Output is correct
7 Correct 0 ms 344 KB Output is correct
8 Correct 0 ms 348 KB Output is correct
9 Correct 0 ms 348 KB Output is correct
10 Correct 0 ms 348 KB Output is correct

Subtask #2
7.0 / 7.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 344 KB Output is correct
2 Correct 0 ms 348 KB Output is correct
3 Correct 0 ms 348 KB Output is correct
4 Correct 1 ms 460 KB Output is correct
5 Correct 1 ms 348 KB Output is correct
6 Correct 0 ms 460 KB Output is correct
7 Correct 0 ms 344 KB Output is correct
8 Correct 0 ms 348 KB Output is correct
9 Correct 0 ms 348 KB Output is correct
10 Correct 0 ms 348 KB Output is correct
11 Correct 1 ms 348 KB Output is correct
12 Correct 0 ms 348 KB Output is correct
13 Correct 0 ms 348 KB Output is correct
14 Correct 0 ms 348 KB Output is correct
15 Correct 0 ms 348 KB Output is correct
16 Correct 1 ms 348 KB Output is correct
17 Correct 1 ms 348 KB Output is correct

Subtask #3
7.0 / 7.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 344 KB Output is correct
2 Correct 0 ms 348 KB Output is correct
3 Correct 0 ms 348 KB Output is correct
4 Correct 1 ms 460 KB Output is correct
5 Correct 1 ms 348 KB Output is correct
6 Correct 0 ms 460 KB Output is correct
7 Correct 0 ms 344 KB Output is correct
8 Correct 0 ms 348 KB Output is correct
9 Correct 0 ms 348 KB Output is correct
10 Correct 0 ms 348 KB Output is correct
11 Correct 1 ms 348 KB Output is correct
12 Correct 0 ms 348 KB Output is correct
13 Correct 0 ms 348 KB Output is correct
14 Correct 0 ms 348 KB Output is correct
15 Correct 0 ms 348 KB Output is correct
16 Correct 1 ms 348 KB Output is correct
17 Correct 1 ms 348 KB Output is correct
18 Correct 2 ms 1884 KB Output is correct
19 Correct 3 ms 1884 KB Output is correct
20 Correct 4 ms 1884 KB Output is correct
21 Correct 3 ms 1372 KB Output is correct
22 Correct 2 ms 1372 KB Output is correct
23 Correct 2 ms 1372 KB Output is correct
24 Correct 2 ms 1372 KB Output is correct

Subtask #4
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 344 KB Output is correct
2 Correct 0 ms 348 KB Output is correct
3 Correct 0 ms 348 KB Output is correct
4 Correct 1 ms 460 KB Output is correct
5 Correct 1 ms 348 KB Output is correct
6 Correct 0 ms 460 KB Output is correct
7 Correct 0 ms 344 KB Output is correct
8 Correct 0 ms 348 KB Output is correct
9 Correct 0 ms 348 KB Output is correct
10 Correct 0 ms 348 KB Output is correct
11 Correct 1 ms 348 KB Output is correct
12 Correct 0 ms 348 KB Output is correct
13 Correct 0 ms 348 KB Output is correct
14 Correct 0 ms 348 KB Output is correct
15 Correct 0 ms 348 KB Output is correct
16 Correct 1 ms 348 KB Output is correct
17 Correct 1 ms 348 KB Output is correct
18 Correct 2 ms 1884 KB Output is correct
19 Correct 3 ms 1884 KB Output is correct
20 Correct 4 ms 1884 KB Output is correct
21 Correct 3 ms 1372 KB Output is correct
22 Correct 2 ms 1372 KB Output is correct
23 Correct 2 ms 1372 KB Output is correct
24 Correct 2 ms 1372 KB Output is correct
25 Correct 0 ms 344 KB Output is correct
26 Correct 136 ms 1116 KB Output is correct
27 Correct 124 ms 1116 KB Output is correct
28 Correct 126 ms 1112 KB Output is correct
29 Correct 125 ms 1116 KB Output is correct
30 Correct 7 ms 860 KB Output is correct
31 Correct 13 ms 916 KB Output is correct
32 Correct 8 ms 856 KB Output is correct
33 Correct 12 ms 860 KB Output is correct

Subtask #5
20.0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 344 KB Output is correct
2 Correct 0 ms 348 KB Output is correct
3 Correct 0 ms 348 KB Output is correct
4 Correct 1 ms 460 KB Output is correct
5 Correct 1 ms 348 KB Output is correct
6 Correct 0 ms 460 KB Output is correct
7 Correct 0 ms 344 KB Output is correct
8 Correct 0 ms 348 KB Output is correct
9 Correct 0 ms 348 KB Output is correct
10 Correct 0 ms 348 KB Output is correct
11 Correct 1 ms 348 KB Output is correct
12 Correct 0 ms 348 KB Output is correct
13 Correct 0 ms 348 KB Output is correct
14 Correct 0 ms 348 KB Output is correct
15 Correct 0 ms 348 KB Output is correct
16 Correct 1 ms 348 KB Output is correct
17 Correct 1 ms 348 KB Output is correct
18 Correct 2 ms 1884 KB Output is correct
19 Correct 3 ms 1884 KB Output is correct
20 Correct 4 ms 1884 KB Output is correct
21 Correct 3 ms 1372 KB Output is correct
22 Correct 2 ms 1372 KB Output is correct
23 Correct 2 ms 1372 KB Output is correct
24 Correct 2 ms 1372 KB Output is correct
25 Correct 122 ms 63540 KB Output is correct
26 Correct 121 ms 61492 KB Output is correct
27 Correct 113 ms 61492 KB Output is correct
28 Correct 104 ms 41808 KB Output is correct
29 Correct 99 ms 41792 KB Output is correct
30 Correct 100 ms 41740 KB Output is correct
31 Correct 105 ms 41808 KB Output is correct

Subtask #6
0 / 23.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 348 KB Output is correct
2 Correct 1 ms 348 KB Output is correct
3 Execution timed out 2047 ms 20372 KB Time limit exceeded
4 Halted 0 ms 0 KB -

Subtask #7
0 / 26.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 344 KB Output is correct
2 Correct 0 ms 348 KB Output is correct
3 Correct 0 ms 348 KB Output is correct
4 Correct 1 ms 460 KB Output is correct
5 Correct 1 ms 348 KB Output is correct
6 Correct 0 ms 460 KB Output is correct
7 Correct 0 ms 344 KB Output is correct
8 Correct 0 ms 348 KB Output is correct
9 Correct 0 ms 348 KB Output is correct
10 Correct 0 ms 348 KB Output is correct
11 Correct 1 ms 348 KB Output is correct
12 Correct 0 ms 348 KB Output is correct
13 Correct 0 ms 348 KB Output is correct
14 Correct 0 ms 348 KB Output is correct
15 Correct 0 ms 348 KB Output is correct
16 Correct 1 ms 348 KB Output is correct
17 Correct 1 ms 348 KB Output is correct
18 Correct 2 ms 1884 KB Output is correct
19 Correct 3 ms 1884 KB Output is correct
20 Correct 4 ms 1884 KB Output is correct
21 Correct 3 ms 1372 KB Output is correct
22 Correct 2 ms 1372 KB Output is correct
23 Correct 2 ms 1372 KB Output is correct
24 Correct 2 ms 1372 KB Output is correct
25 Correct 0 ms 344 KB Output is correct
26 Correct 136 ms 1116 KB Output is correct
27 Correct 124 ms 1116 KB Output is correct
28 Correct 126 ms 1112 KB Output is correct
29 Correct 125 ms 1116 KB Output is correct
30 Correct 7 ms 860 KB Output is correct
31 Correct 13 ms 916 KB Output is correct
32 Correct 8 ms 856 KB Output is correct
33 Correct 12 ms 860 KB Output is correct
34 Correct 122 ms 63540 KB Output is correct
35 Correct 121 ms 61492 KB Output is correct
36 Correct 113 ms 61492 KB Output is correct
37 Correct 104 ms 41808 KB Output is correct
38 Correct 99 ms 41792 KB Output is correct
39 Correct 100 ms 41740 KB Output is correct
40 Correct 105 ms 41808 KB Output is correct
41 Correct 1 ms 348 KB Output is correct
42 Correct 1 ms 348 KB Output is correct
43 Execution timed out 2047 ms 20372 KB Time limit exceeded
44 Halted 0 ms 0 KB -