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Submission #894427

# Submission time Handle Problem Language Result Execution time Memory
894427 2023-12-28T09:15:07 Z vjudge1 The Xana coup (BOI21_xanadu) C++17
100 / 100
 94 ms 51100 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 4700 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 4700 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 4740 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 4952 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 2 ms 4700 KB Output is correct

Subtask #3
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 94 ms 50856 KB Output is correct
2 Correct 72 ms 50260 KB Output is correct
3 Correct 75 ms 51028 KB Output is correct

Subtask #4
40.0 / 40.0

# Verdict Execution time Memory Grader output
1 Correct 76 ms 50740 KB Output is correct
2 Correct 74 ms 50256 KB Output is correct
3 Correct 74 ms 51100 KB Output is correct
4 Correct 54 ms 10556 KB Output is correct
5 Correct 50 ms 11096 KB Output is correct
6 Correct 59 ms 11304 KB Output is correct
7 Correct 2 ms 4696 KB Output is correct
8 Correct 23 ms 7332 KB Output is correct
9 Correct 45 ms 11100 KB Output is correct
10 Correct 47 ms 11292 KB Output is correct
11 Correct 49 ms 13908 KB Output is correct
12 Correct 49 ms 14420 KB Output is correct
13 Correct 46 ms 11176 KB Output is correct
14 Correct 44 ms 11508 KB Output is correct

Subtask #5
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 4700 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 4740 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 4952 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 2 ms 4700 KB Output is correct
17 Correct 94 ms 50856 KB Output is correct
18 Correct 72 ms 50260 KB Output is correct
19 Correct 75 ms 51028 KB Output is correct
20 Correct 76 ms 50740 KB Output is correct
21 Correct 74 ms 50256 KB Output is correct
22 Correct 74 ms 51100 KB Output is correct
23 Correct 54 ms 10556 KB Output is correct
24 Correct 50 ms 11096 KB Output is correct
25 Correct 59 ms 11304 KB Output is correct
26 Correct 2 ms 4696 KB Output is correct
27 Correct 23 ms 7332 KB Output is correct
28 Correct 45 ms 11100 KB Output is correct
29 Correct 47 ms 11292 KB Output is correct
30 Correct 49 ms 13908 KB Output is correct
31 Correct 49 ms 14420 KB Output is correct
32 Correct 46 ms 11176 KB Output is correct
33 Correct 44 ms 11508 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 72 ms 50664 KB Output is correct
46 Correct 86 ms 50260 KB Output is correct
47 Correct 74 ms 50872 KB Output is correct
48 Correct 41 ms 10524 KB Output is correct
49 Correct 60 ms 11164 KB Output is correct
50 Correct 46 ms 11100 KB Output is correct
51 Correct 2 ms 4700 KB Output is correct
52 Correct 17 ms 6692 KB Output is correct
53 Correct 55 ms 11092 KB Output is correct
54 Correct 46 ms 11092 KB Output is correct
55 Correct 70 ms 13916 KB Output is correct
56 Correct 84 ms 14540 KB Output is correct
57 Correct 47 ms 11144 KB Output is correct
58 Correct 52 ms 11852 KB Output is correct
59 Correct 15 ms 6744 KB Output is correct
60 Correct 41 ms 10388 KB Output is correct
61 Correct 45 ms 10836 KB Output is correct
62 Correct 46 ms 11088 KB Output is correct
63 Correct 45 ms 11092 KB Output is correct
64 Correct 61 ms 11348 KB Output is correct
65 Correct 44 ms 11296 KB Output is correct
66 Correct 44 ms 11352 KB Output is correct
67 Correct 37 ms 11200 KB Output is correct
68 Correct 35 ms 11204 KB Output is correct
69 Correct 37 ms 11208 KB Output is correct
70 Correct 52 ms 11104 KB Output is correct