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Submission #847440

# Submission time Handle Problem Language Result Execution time Memory
847440 2023-09-09T16:18:14 Z MinaRagy06 The Xana coup (BOI21_xanadu) C++17
100 / 100
 64 ms 28088 KB 
#include <bits/stdc++.h>
using namespace std;
typedef int64_t ll;

const int N = 100'005;
int n, dp[N][2][2], a[N];
vector<int> adj[N];
int dfs(int i, int par, int parf, int curf) {
    if (~dp[i][parf][curf]) {
        return dp[i][parf][curf];
    }
    vector<int> newadj;
    for (auto nxt : adj[i]) {
        if (nxt == par) continue;
        newadj.push_back(nxt);
        dfs(nxt, i, curf, 0);
        dfs(nxt, i, curf, 1);
    }
    adj[i] = newadj;
    int m = adj[i].size();
    int dp2[m + 1][2]{};
    memset(dp2, '?', sizeof dp2);
    dp2[m][a[i] ^ parf ^ curf] = curf;
    for (int j = m - 1; j >= 0; j--) {
        for (int k = 0; k < 2; k++) {
            dp2[j][k] = min(dp2[j + 1][k ^ 1] + dp[adj[i][j]][curf][1], dp2[j + 1][k] + dp[adj[i][j]][curf][0]);
            dp2[j][k] = min(dp2[j][k], int(1e9));
        }
    }
    return dp[i][parf][curf] = dp2[0][0];
}
int main() {
    ios_base::sync_with_stdio(0), cin.tie(0);
    cin >> n;
    for (int i = 1, u, v; i < n; i++) {
        cin >> u >> v;
        adj[u].push_back(v);
        adj[v].push_back(u);
    }
    for (int i = 1; i <= n; i++) {
        cin >> a[i];
    }
    memset(dp, -1, sizeof dp);
    int ans1 = dfs(1, 0, 0, 0);
    int ans2 = dfs(1, 0, 0, 1);
    if (min(ans1, ans2) >= int(1e9)) {
        cout << "impossible\n";
    } else {
        cout << min(ans1, ans2) << '\n';
    }
    return 0;
}

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 4700 KB Output is correct
8 Correct 1 ms 4700 KB Output is correct
9 Correct 2 ms 4700 KB Output is correct
10 Correct 1 ms 4700 KB Output is correct
11 Correct 1 ms 4712 KB Output is correct
12 Correct 1 ms 4696 KB Output is correct
13 Correct 1 ms 4700 KB Output is correct
14 Correct 1 ms 4608 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 59 ms 27896 KB Output is correct
2 Correct 60 ms 27732 KB Output is correct
3 Correct 58 ms 28088 KB Output is correct

Subtask #4
40.0 / 40.0

# Verdict Execution time Memory Grader output
1 Correct 57 ms 27844 KB Output is correct
2 Correct 61 ms 27740 KB Output is correct
3 Correct 63 ms 27988 KB Output is correct
4 Correct 41 ms 7516 KB Output is correct
5 Correct 48 ms 7768 KB Output is correct
6 Correct 50 ms 7872 KB Output is correct
7 Correct 1 ms 4700 KB Output is correct
8 Correct 16 ms 5968 KB Output is correct
9 Correct 46 ms 8024 KB Output is correct
10 Correct 48 ms 8024 KB Output is correct
11 Correct 44 ms 9444 KB Output is correct
12 Correct 46 ms 9552 KB Output is correct
13 Correct 41 ms 7512 KB Output is correct
14 Correct 46 ms 7768 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 4700 KB Output is correct
8 Correct 1 ms 4700 KB Output is correct
9 Correct 2 ms 4700 KB Output is correct
10 Correct 1 ms 4700 KB Output is correct
11 Correct 1 ms 4712 KB Output is correct
12 Correct 1 ms 4696 KB Output is correct
13 Correct 1 ms 4700 KB Output is correct
14 Correct 1 ms 4608 KB Output is correct
15 Correct 1 ms 4700 KB Output is correct
16 Correct 1 ms 4700 KB Output is correct
17 Correct 59 ms 27896 KB Output is correct
18 Correct 60 ms 27732 KB Output is correct
19 Correct 58 ms 28088 KB Output is correct
20 Correct 57 ms 27844 KB Output is correct
21 Correct 61 ms 27740 KB Output is correct
22 Correct 63 ms 27988 KB Output is correct
23 Correct 41 ms 7516 KB Output is correct
24 Correct 48 ms 7768 KB Output is correct
25 Correct 50 ms 7872 KB Output is correct
26 Correct 1 ms 4700 KB Output is correct
27 Correct 16 ms 5968 KB Output is correct
28 Correct 46 ms 8024 KB Output is correct
29 Correct 48 ms 8024 KB Output is correct
30 Correct 44 ms 9444 KB Output is correct
31 Correct 46 ms 9552 KB Output is correct
32 Correct 41 ms 7512 KB Output is correct
33 Correct 46 ms 7768 KB Output is correct
34 Correct 1 ms 4700 KB Output is correct
35 Correct 1 ms 4696 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 4696 KB Output is correct
39 Correct 1 ms 4696 KB Output is correct
40 Correct 1 ms 4696 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 4696 KB Output is correct
45 Correct 64 ms 27988 KB Output is correct
46 Correct 58 ms 27732 KB Output is correct
47 Correct 61 ms 28084 KB Output is correct
48 Correct 41 ms 7516 KB Output is correct
49 Correct 46 ms 7812 KB Output is correct
50 Correct 48 ms 7772 KB Output is correct
51 Correct 1 ms 4700 KB Output is correct
52 Correct 16 ms 5868 KB Output is correct
53 Correct 55 ms 7992 KB Output is correct
54 Correct 46 ms 8028 KB Output is correct
55 Correct 48 ms 9300 KB Output is correct
56 Correct 46 ms 9556 KB Output is correct
57 Correct 41 ms 7512 KB Output is correct
58 Correct 44 ms 7772 KB Output is correct
59 Correct 16 ms 5920 KB Output is correct
60 Correct 50 ms 7508 KB Output is correct
61 Correct 47 ms 7980 KB Output is correct
62 Correct 46 ms 8068 KB Output is correct
63 Correct 46 ms 7848 KB Output is correct
64 Correct 48 ms 8020 KB Output is correct
65 Correct 37 ms 8412 KB Output is correct
66 Correct 36 ms 8284 KB Output is correct
67 Correct 37 ms 9936 KB Output is correct
68 Correct 36 ms 9936 KB Output is correct
69 Correct 35 ms 9776 KB Output is correct
70 Correct 35 ms 9928 KB Output is correct