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Submission #725766

# Submission time Handle Problem Language Result Execution time Memory
725766 2023-04-18T03:13:25 Z LittleCube The Xana coup (BOI21_xanadu) C++14
100 / 100
 94 ms 22768 KB 
#include <bits/stdc++.h>
#define ll long long
#define pii pair<int, int>
#define pll pair<ll, ll>
#define F first
#define S second
using namespace std;

// dp[op][cur]
// op = 1: all subtree cur == 0
// op = 0: all subtree cur == 1
ll N, p[100005], a[100005], dp[100005][2][2];
vector<int> E[100005];

void dfs(int u)
{
    // dp[u][0][0] = dp[u][0][1] = dp[u][1][0] = dp[u][1][1] = N + 1;
    ll dcur = a[u], ncur = a[u], d = N + 1, n = N + 1, dcost = 0, ncost = 0;
    for (int v : E[u])
        if (p[u] != v)
        {
            //cerr << u << " -> " << v << '\n';
            p[v] = u;
            dfs(v);

            dcur ^= (dp[v][0][1] < dp[v][1][1] ? 0 : 1);
            dcost += min(dp[v][0][1], dp[v][1][1]);
            d = min(d, abs(dp[v][0][1] - dp[v][1][1]));

            ncur ^= (dp[v][0][0] < dp[v][1][0] ? 0 : 1);
            ncost += min(dp[v][0][0], dp[v][1][0]);
            n = min(n, abs(dp[v][0][0] - dp[v][1][0]));
        }
    dp[u][1][dcur ^ 1] = dcost + 1;
    dp[u][1][dcur] = dcost + d + 1;
    dp[u][0][ncur] = ncost;
    dp[u][0][ncur ^ 1] = ncost + n;
    //cerr << u << ": " << dp[u][0][0] << ' ' << dp[u][0][1] << ' ' << dp[u][1][0] << ' ' << dp[u][1][1] << '\n';
}

signed main()
{
    ios::sync_with_stdio(0);
    cin.tie(0), cout.tie(0);
    cin >> N;
    for (int i = 1; i < N; i++)
    {
        int u, v;
        cin >> u >> v;
        E[u].emplace_back(v);
        E[v].emplace_back(u);
    }
    for (int i = 1; i <= N; i++)
        cin >> a[i];
    dfs(1);
    int ans = min(dp[1][0][0], dp[1][1][0]);
    if (ans > N)
        cout << "impossible\n";
    else
        cout << ans << '\n';
}

Subtask #1
5.0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 2644 KB Output is correct
2 Correct 2 ms 2644 KB Output is correct
3 Correct 2 ms 2644 KB Output is correct
4 Correct 2 ms 2644 KB Output is correct
5 Correct 2 ms 2644 KB Output is correct

Subtask #2
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 2644 KB Output is correct
2 Correct 2 ms 2644 KB Output is correct
3 Correct 2 ms 2644 KB Output is correct
4 Correct 2 ms 2644 KB Output is correct
5 Correct 2 ms 2644 KB Output is correct
6 Correct 2 ms 2688 KB Output is correct
7 Correct 2 ms 2644 KB Output is correct
8 Correct 2 ms 2644 KB Output is correct
9 Correct 2 ms 2680 KB Output is correct
10 Correct 2 ms 2644 KB Output is correct
11 Correct 2 ms 2644 KB Output is correct
12 Correct 3 ms 2644 KB Output is correct
13 Correct 2 ms 2644 KB Output is correct
14 Correct 2 ms 2644 KB Output is correct
15 Correct 2 ms 2644 KB Output is correct
16 Correct 1 ms 2644 KB Output is correct

Subtask #3
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 62 ms 22720 KB Output is correct
2 Correct 55 ms 22396 KB Output is correct
3 Correct 63 ms 22756 KB Output is correct

Subtask #4
40.0 / 40.0

# Verdict Execution time Memory Grader output
1 Correct 65 ms 22672 KB Output is correct
2 Correct 78 ms 22388 KB Output is correct
3 Correct 56 ms 22768 KB Output is correct
4 Correct 51 ms 10840 KB Output is correct
5 Correct 61 ms 11648 KB Output is correct
6 Correct 85 ms 11724 KB Output is correct
7 Correct 2 ms 2680 KB Output is correct
8 Correct 19 ms 5780 KB Output is correct
9 Correct 56 ms 11768 KB Output is correct
10 Correct 56 ms 11952 KB Output is correct
11 Correct 68 ms 12480 KB Output is correct
12 Correct 67 ms 12836 KB Output is correct
13 Correct 94 ms 11372 KB Output is correct
14 Correct 92 ms 11724 KB Output is correct

Subtask #5
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 2644 KB Output is correct
2 Correct 2 ms 2644 KB Output is correct
3 Correct 2 ms 2644 KB Output is correct
4 Correct 2 ms 2644 KB Output is correct
5 Correct 2 ms 2644 KB Output is correct
6 Correct 2 ms 2688 KB Output is correct
7 Correct 2 ms 2644 KB Output is correct
8 Correct 2 ms 2644 KB Output is correct
9 Correct 2 ms 2680 KB Output is correct
10 Correct 2 ms 2644 KB Output is correct
11 Correct 2 ms 2644 KB Output is correct
12 Correct 3 ms 2644 KB Output is correct
13 Correct 2 ms 2644 KB Output is correct
14 Correct 2 ms 2644 KB Output is correct
15 Correct 2 ms 2644 KB Output is correct
16 Correct 1 ms 2644 KB Output is correct
17 Correct 62 ms 22720 KB Output is correct
18 Correct 55 ms 22396 KB Output is correct
19 Correct 63 ms 22756 KB Output is correct
20 Correct 65 ms 22672 KB Output is correct
21 Correct 78 ms 22388 KB Output is correct
22 Correct 56 ms 22768 KB Output is correct
23 Correct 51 ms 10840 KB Output is correct
24 Correct 61 ms 11648 KB Output is correct
25 Correct 85 ms 11724 KB Output is correct
26 Correct 2 ms 2680 KB Output is correct
27 Correct 19 ms 5780 KB Output is correct
28 Correct 56 ms 11768 KB Output is correct
29 Correct 56 ms 11952 KB Output is correct
30 Correct 68 ms 12480 KB Output is correct
31 Correct 67 ms 12836 KB Output is correct
32 Correct 94 ms 11372 KB Output is correct
33 Correct 92 ms 11724 KB Output is correct
34 Correct 3 ms 2676 KB Output is correct
35 Correct 2 ms 2680 KB Output is correct
36 Correct 2 ms 2644 KB Output is correct
37 Correct 2 ms 2644 KB Output is correct
38 Correct 2 ms 2644 KB Output is correct
39 Correct 3 ms 2644 KB Output is correct
40 Correct 3 ms 2644 KB Output is correct
41 Correct 2 ms 2644 KB Output is correct
42 Correct 3 ms 2676 KB Output is correct
43 Correct 3 ms 2644 KB Output is correct
44 Correct 2 ms 2644 KB Output is correct
45 Correct 75 ms 22652 KB Output is correct
46 Correct 70 ms 22448 KB Output is correct
47 Correct 72 ms 22760 KB Output is correct
48 Correct 58 ms 10828 KB Output is correct
49 Correct 50 ms 11528 KB Output is correct
50 Correct 56 ms 11828 KB Output is correct
51 Correct 2 ms 2644 KB Output is correct
52 Correct 14 ms 5736 KB Output is correct
53 Correct 80 ms 11792 KB Output is correct
54 Correct 67 ms 11896 KB Output is correct
55 Correct 58 ms 12520 KB Output is correct
56 Correct 58 ms 12756 KB Output is correct
57 Correct 63 ms 11264 KB Output is correct
58 Correct 58 ms 11724 KB Output is correct
59 Correct 22 ms 5744 KB Output is correct
60 Correct 53 ms 11056 KB Output is correct
61 Correct 76 ms 11732 KB Output is correct
62 Correct 61 ms 11908 KB Output is correct
63 Correct 68 ms 11876 KB Output is correct
64 Correct 83 ms 11924 KB Output is correct
65 Correct 51 ms 12372 KB Output is correct
66 Correct 48 ms 12296 KB Output is correct
67 Correct 41 ms 12228 KB Output is correct
68 Correct 50 ms 12140 KB Output is correct
69 Correct 43 ms 12164 KB Output is correct
70 Correct 41 ms 12140 KB Output is correct