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Submission #894454

# Submission time Handle Problem Language Result Execution time Memory
894454 2023-12-28T09:54:14 Z d4xn The Xana coup (BOI21_xanadu) C++17
100 / 100
 83 ms 49784 KB 
#include <bits/stdc++.h>
using namespace std;

#define int long long

const int N = 1e5+5, inf = INT_MAX;

int n, dp[2][2][N]; // me he pulsado a mi mismo?, soy 0 o 1?, nodo
vector<int> adj[N];
bitset<N> bt;

void dfs(int x, int p) {
  vector<vector<int>> sum(2, vector<int>(2, 0));
  vector<int> mnSum(2, 0);
  vector<int> cnt(2, 0);
  vector<int> mnDif(2, inf);

  for (int& y : adj[x]) {
    if (y == p) continue;
    dfs(y, x);

    for (int i = 0; i < 2; i++) {
      for (int j = 0; j < 2; j++) {
        sum[i][j] += dp[i][j][y];
      }
    }

    for (int i = 0; i < 2; i++) {
      if (dp[0][i][y] < dp[1][i][y]) {
        mnSum[i] += dp[0][i][y];
        mnDif[i] = min(mnDif[i], dp[1][i][y] - dp[0][i][y]);
      }
      else {
        mnSum[i] += dp[1][i][y];
        cnt[i]++;
        mnDif[i] = min(mnDif[i], dp[0][i][y] - dp[1][i][y]);
      }
    }
  }

  if (!bt[x]) {
    dp[0][0][x] = mnSum[0] + (cnt[0] % 2 ? mnDif[0] : 0);
    dp[0][1][x] = mnSum[0] + (!(cnt[0] % 2) ? mnDif[0] : 0);
    dp[1][0][x] = 1 + mnSum[1] + (!(cnt[1] % 2) ? mnDif[1] : 0);
    dp[1][1][x] = 1 + mnSum[1] + (cnt[1] % 2 ? mnDif[1] : 0);
  }
  else {
    dp[0][0][x] = mnSum[0] + (!(cnt[0] % 2) ? mnDif[0] : 0);
    dp[0][1][x] = mnSum[0] + (cnt[0] % 2 ? mnDif[0] : 0);
    dp[1][0][x] = 1 + mnSum[1] + (cnt[1] % 2 ? mnDif[1] : 0);
    dp[1][1][x] = 1 + mnSum[1] + (!(cnt[1] % 2) ? mnDif[1] : 0);
  }
}

signed main() {
  ios::sync_with_stdio(false); cin.tie(nullptr);

  cin >> n;
  for (int i = 0; i < n-1; i++) {
    int x, y;
    cin >> x >> y;
    x--; y--;
    adj[x].push_back(y);
    adj[y].push_back(x);
  }
  for (int i = 0; i < n; i++) {
    int x;
    cin >> x;
    if (x) bt[i] = 1;
  }
  dfs(0, 0);

  int ans = min(dp[0][0][0], dp[1][0][0]);
  if (ans>= inf) cout << "impossible\n";
  else cout << ans << "\n";
}

Subtask #1
5.0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 4696 KB Output is correct
2 Correct 1 ms 4700 KB Output is correct
3 Correct 1 ms 4700 KB Output is correct
4 Correct 1 ms 4700 KB Output is correct
5 Correct 1 ms 4700 KB Output is correct

Subtask #2
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 4696 KB Output is correct
2 Correct 1 ms 4700 KB Output is correct
3 Correct 1 ms 4700 KB Output is correct
4 Correct 1 ms 4700 KB Output is correct
5 Correct 1 ms 4700 KB Output is correct
6 Correct 1 ms 4700 KB Output is correct
7 Correct 1 ms 4700 KB Output is correct
8 Correct 1 ms 4700 KB Output is correct
9 Correct 1 ms 4700 KB Output is correct
10 Correct 1 ms 4700 KB Output is correct
11 Correct 1 ms 4700 KB Output is correct
12 Correct 1 ms 4700 KB Output is correct
13 Correct 1 ms 4700 KB Output is correct
14 Correct 1 ms 4700 KB Output is correct
15 Correct 1 ms 4700 KB Output is correct
16 Correct 1 ms 4700 KB Output is correct

Subtask #3
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 73 ms 49308 KB Output is correct
2 Correct 69 ms 48976 KB Output is correct
3 Correct 73 ms 49748 KB Output is correct

Subtask #4
40.0 / 40.0

# Verdict Execution time Memory Grader output
1 Correct 73 ms 49316 KB Output is correct
2 Correct 71 ms 48980 KB Output is correct
3 Correct 76 ms 49760 KB Output is correct
4 Correct 43 ms 9188 KB Output is correct
5 Correct 45 ms 9844 KB Output is correct
6 Correct 48 ms 9764 KB Output is correct
7 Correct 1 ms 4700 KB Output is correct
8 Correct 16 ms 6276 KB Output is correct
9 Correct 61 ms 9872 KB Output is correct
10 Correct 56 ms 9820 KB Output is correct
11 Correct 49 ms 12584 KB Output is correct
12 Correct 51 ms 13140 KB Output is correct
13 Correct 42 ms 9808 KB Output is correct
14 Correct 48 ms 10076 KB Output is correct

Subtask #5
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 4696 KB Output is correct
2 Correct 1 ms 4700 KB Output is correct
3 Correct 1 ms 4700 KB Output is correct
4 Correct 1 ms 4700 KB Output is correct
5 Correct 1 ms 4700 KB Output is correct
6 Correct 1 ms 4700 KB Output is correct
7 Correct 1 ms 4700 KB Output is correct
8 Correct 1 ms 4700 KB Output is correct
9 Correct 1 ms 4700 KB Output is correct
10 Correct 1 ms 4700 KB Output is correct
11 Correct 1 ms 4700 KB Output is correct
12 Correct 1 ms 4700 KB Output is correct
13 Correct 1 ms 4700 KB Output is correct
14 Correct 1 ms 4700 KB Output is correct
15 Correct 1 ms 4700 KB Output is correct
16 Correct 1 ms 4700 KB Output is correct
17 Correct 73 ms 49308 KB Output is correct
18 Correct 69 ms 48976 KB Output is correct
19 Correct 73 ms 49748 KB Output is correct
20 Correct 73 ms 49316 KB Output is correct
21 Correct 71 ms 48980 KB Output is correct
22 Correct 76 ms 49760 KB Output is correct
23 Correct 43 ms 9188 KB Output is correct
24 Correct 45 ms 9844 KB Output is correct
25 Correct 48 ms 9764 KB Output is correct
26 Correct 1 ms 4700 KB Output is correct
27 Correct 16 ms 6276 KB Output is correct
28 Correct 61 ms 9872 KB Output is correct
29 Correct 56 ms 9820 KB Output is correct
30 Correct 49 ms 12584 KB Output is correct
31 Correct 51 ms 13140 KB Output is correct
32 Correct 42 ms 9808 KB Output is correct
33 Correct 48 ms 10076 KB Output is correct
34 Correct 1 ms 4696 KB Output is correct
35 Correct 1 ms 4700 KB Output is correct
36 Correct 1 ms 4700 KB Output is correct
37 Correct 1 ms 4700 KB Output is correct
38 Correct 1 ms 4700 KB Output is correct
39 Correct 1 ms 4700 KB Output is correct
40 Correct 1 ms 4700 KB Output is correct
41 Correct 1 ms 4700 KB Output is correct
42 Correct 1 ms 4700 KB Output is correct
43 Correct 1 ms 4700 KB Output is correct
44 Correct 1 ms 4700 KB Output is correct
45 Correct 83 ms 49540 KB Output is correct
46 Correct 69 ms 48968 KB Output is correct
47 Correct 78 ms 49784 KB Output is correct
48 Correct 40 ms 9308 KB Output is correct
49 Correct 46 ms 9840 KB Output is correct
50 Correct 46 ms 9728 KB Output is correct
51 Correct 1 ms 4700 KB Output is correct
52 Correct 16 ms 6492 KB Output is correct
53 Correct 45 ms 9556 KB Output is correct
54 Correct 53 ms 9944 KB Output is correct
55 Correct 49 ms 12628 KB Output is correct
56 Correct 48 ms 13136 KB Output is correct
57 Correct 44 ms 9896 KB Output is correct
58 Correct 46 ms 10076 KB Output is correct
59 Correct 15 ms 6232 KB Output is correct
60 Correct 41 ms 9044 KB Output is correct
61 Correct 46 ms 9496 KB Output is correct
62 Correct 46 ms 9820 KB Output is correct
63 Correct 47 ms 9652 KB Output is correct
64 Correct 45 ms 9812 KB Output is correct
65 Correct 40 ms 10120 KB Output is correct
66 Correct 40 ms 10064 KB Output is correct
67 Correct 35 ms 9680 KB Output is correct
68 Correct 35 ms 9868 KB Output is correct
69 Correct 34 ms 9680 KB Output is correct
70 Correct 44 ms 10020 KB Output is correct