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Submission #506386

# Submission time Handle Problem Language Result Execution time Memory
506386 2022-01-12T03:25:04 Z Elegia The Xana coup (BOI21_xanadu) C++17
100 / 100
 73 ms 16904 KB 
#include <bits/stdc++.h>

using ull = unsigned long long;

using namespace std;

const int P = 998244353;

int norm(int x) { return x >= P ? x - P : x; }
int reduce(int x) { return x < 0 ? x + P : x; }
int neg(int x) { return x ? P - x : 0; }
void add(int& x, int y) { if ((x += y - P) < 0) x += P; }
void sub(int& x, int y) { if ((x -= y) < 0) x += P; }
void fam(int& x, int y, int z) { x = (x + y * (ull)z) % P; }
int mpow(int x, unsigned k) {
	if (k == 0) return 1;
	int ret = mpow(x * (ull)x % P, k >> 1);
	if (k & 1) ret = ret * (ull)x % P;
	return ret;
}
int quo2(int x) { return ((x & 1) ? x + P : x) >> 1; }

const int _ = 100010;

vector<int> G[_];
int f[_], dp[_][2][2];

void dfs(int u, int p) {
	dp[u][0][f[u]] = 0; dp[u][1][f[u] ^ 1] = 1;
	dp[u][0][f[u] ^ 1] = dp[u][1][f[u]] = _;
	for (int v : G[u]) if (p != v) {
		dfs(v, u);
		static int tmp[2][2];
		for (int a = 0; a <= 1; ++a)
			for (int b = 0; b <= 1; ++b) {
				tmp[a][b] = _;
				for (int c = 0; c <= 1; ++c)
					tmp[a][b] = min(tmp[a][b], dp[u][a][b ^ c] + dp[v][c][a]);
			}
		memcpy(dp[u], tmp, sizeof(tmp));
	}
}

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

	int N; cin >> N;
	for (int rep = 1; rep != N; ++rep) {
		int u, v; cin >> u >> v;
		G[u].push_back(v); G[v].push_back(u);
	}
	for (int i = 1; i <= N; ++i) cin >> f[i];
	dfs(1, 0);
	int ans = min(dp[1][0][0], dp[1][1][0]);
	if (ans <= N) cout << ans << '\n';
	else cout << "impossible\n";

	return 0;
}

Subtask #1
5.0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 2636 KB Output is correct
2 Correct 1 ms 2636 KB Output is correct
3 Correct 2 ms 2672 KB Output is correct
4 Correct 2 ms 2636 KB Output is correct
5 Correct 1 ms 2636 KB Output is correct

Subtask #2
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 2636 KB Output is correct
2 Correct 1 ms 2636 KB Output is correct
3 Correct 2 ms 2672 KB Output is correct
4 Correct 2 ms 2636 KB Output is correct
5 Correct 1 ms 2636 KB Output is correct
6 Correct 2 ms 2636 KB Output is correct
7 Correct 1 ms 2636 KB Output is correct
8 Correct 2 ms 2636 KB Output is correct
9 Correct 2 ms 2636 KB Output is correct
10 Correct 1 ms 2680 KB Output is correct
11 Correct 1 ms 2636 KB Output is correct
12 Correct 2 ms 2636 KB Output is correct
13 Correct 2 ms 2636 KB Output is correct
14 Correct 1 ms 2636 KB Output is correct
15 Correct 2 ms 2636 KB Output is correct
16 Correct 2 ms 2636 KB Output is correct

Subtask #3
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 57 ms 16784 KB Output is correct
2 Correct 54 ms 16636 KB Output is correct
3 Correct 53 ms 16904 KB Output is correct

Subtask #4
40.0 / 40.0

# Verdict Execution time Memory Grader output
1 Correct 59 ms 16712 KB Output is correct
2 Correct 64 ms 16664 KB Output is correct
3 Correct 48 ms 16888 KB Output is correct
4 Correct 44 ms 8376 KB Output is correct
5 Correct 56 ms 8848 KB Output is correct
6 Correct 55 ms 9064 KB Output is correct
7 Correct 2 ms 2636 KB Output is correct
8 Correct 19 ms 4804 KB Output is correct
9 Correct 61 ms 8956 KB Output is correct
10 Correct 59 ms 9080 KB Output is correct
11 Correct 47 ms 9456 KB Output is correct
12 Correct 73 ms 9708 KB Output is correct
13 Correct 48 ms 8576 KB Output is correct
14 Correct 44 ms 9028 KB Output is correct

Subtask #5
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 2636 KB Output is correct
2 Correct 1 ms 2636 KB Output is correct
3 Correct 2 ms 2672 KB Output is correct
4 Correct 2 ms 2636 KB Output is correct
5 Correct 1 ms 2636 KB Output is correct
6 Correct 2 ms 2636 KB Output is correct
7 Correct 1 ms 2636 KB Output is correct
8 Correct 2 ms 2636 KB Output is correct
9 Correct 2 ms 2636 KB Output is correct
10 Correct 1 ms 2680 KB Output is correct
11 Correct 1 ms 2636 KB Output is correct
12 Correct 2 ms 2636 KB Output is correct
13 Correct 2 ms 2636 KB Output is correct
14 Correct 1 ms 2636 KB Output is correct
15 Correct 2 ms 2636 KB Output is correct
16 Correct 2 ms 2636 KB Output is correct
17 Correct 57 ms 16784 KB Output is correct
18 Correct 54 ms 16636 KB Output is correct
19 Correct 53 ms 16904 KB Output is correct
20 Correct 59 ms 16712 KB Output is correct
21 Correct 64 ms 16664 KB Output is correct
22 Correct 48 ms 16888 KB Output is correct
23 Correct 44 ms 8376 KB Output is correct
24 Correct 56 ms 8848 KB Output is correct
25 Correct 55 ms 9064 KB Output is correct
26 Correct 2 ms 2636 KB Output is correct
27 Correct 19 ms 4804 KB Output is correct
28 Correct 61 ms 8956 KB Output is correct
29 Correct 59 ms 9080 KB Output is correct
30 Correct 47 ms 9456 KB Output is correct
31 Correct 73 ms 9708 KB Output is correct
32 Correct 48 ms 8576 KB Output is correct
33 Correct 44 ms 9028 KB Output is correct
34 Correct 1 ms 2636 KB Output is correct
35 Correct 1 ms 2636 KB Output is correct
36 Correct 1 ms 2636 KB Output is correct
37 Correct 2 ms 2636 KB Output is correct
38 Correct 2 ms 2636 KB Output is correct
39 Correct 2 ms 2676 KB Output is correct
40 Correct 2 ms 2636 KB Output is correct
41 Correct 2 ms 2636 KB Output is correct
42 Correct 1 ms 2680 KB Output is correct
43 Correct 2 ms 2636 KB Output is correct
44 Correct 1 ms 2636 KB Output is correct
45 Correct 47 ms 16712 KB Output is correct
46 Correct 52 ms 16540 KB Output is correct
47 Correct 52 ms 16876 KB Output is correct
48 Correct 40 ms 8396 KB Output is correct
49 Correct 57 ms 8928 KB Output is correct
50 Correct 49 ms 9080 KB Output is correct
51 Correct 3 ms 2676 KB Output is correct
52 Correct 16 ms 4812 KB Output is correct
53 Correct 47 ms 9044 KB Output is correct
54 Correct 49 ms 9088 KB Output is correct
55 Correct 46 ms 9512 KB Output is correct
56 Correct 50 ms 9760 KB Output is correct
57 Correct 47 ms 8732 KB Output is correct
58 Correct 46 ms 9068 KB Output is correct
59 Correct 14 ms 4740 KB Output is correct
60 Correct 43 ms 8388 KB Output is correct
61 Correct 45 ms 9032 KB Output is correct
62 Correct 46 ms 9056 KB Output is correct
63 Correct 48 ms 9168 KB Output is correct
64 Correct 62 ms 9112 KB Output is correct
65 Correct 52 ms 9540 KB Output is correct
66 Correct 61 ms 9532 KB Output is correct
67 Correct 35 ms 9488 KB Output is correct
68 Correct 51 ms 9404 KB Output is correct
69 Correct 34 ms 9380 KB Output is correct
70 Correct 35 ms 9376 KB Output is correct