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Submission #672846

# Submission time Handle Problem Language Result Execution time Memory
672846 2022-12-18T12:15:24 Z Kahou The Xana coup (BOI21_xanadu) C++14
100 / 100
 82 ms 18652 KB 
/* In the name of God, aka Allah */
// let this be mytemp.cpp
#include<bits/stdc++.h>
using namespace std;
#define F first
#define S second
#define endl '\n'
#define mk make_pair
typedef long long ll;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;

const int N = 1e5 + 50;
int n, c[N], dp[N][2][2];
vector<int> adj[N];

void dfs(int u, int p) {
	dp[u][0][0] = dp[u][0][1] = dp[u][1][0] = dp[u][1][1] = N;
	int s0 = 0, s1 = 1, m0 = N, m1 = N, c0 = c[u], c1 = c[u]^1;
	for (int v:adj[u]) {
		if (v == p) continue;
		dfs(v, u);
		s0 += min(dp[v][0][0], dp[v][0][1]);
		s1 += min(dp[v][1][0], dp[v][1][1]);
		c0 ^= (dp[v][0][1] < dp[v][0][0]);
		c1 ^= (dp[v][1][1] < dp[v][1][0]);
		m0 = min(m0, abs(dp[v][0][0]-dp[v][0][1]));
		m1 = min(m1, abs(dp[v][1][0]-dp[v][1][1]));
	}
	dp[u][c0][0] = min(dp[u][c0][0], s0);
	dp[u][c0^1][0] = min(dp[u][c0^1][0], s0+m0);
	dp[u][c1][1] = min(dp[u][c1][1], s1);
	dp[u][c1^1][1] = min(dp[u][c1^1][1], s1+m1);
}

void solve() {
	cin >> n;
	for (int i = 1; i <= n-1; i++) {
		int u, v;
		cin >> u >> v;
		adj[u].push_back(v), adj[v].push_back(u);
	}
	for (int u = 1; u <= n; u++) {
		cin >> c[u];
	}
	dfs(1, 0);
	int ans = min(dp[1][0][0], dp[1][0][1]);
	if (ans >= N) return cout << "impossible" << endl, void();
	cout << ans << endl;
}
int main() {
	ios::sync_with_stdio(0), cin.tie(0), cout.tie(0);
	solve();
	return 0;
}

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 1 ms 2644 KB Output is correct
4 Correct 3 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 1 ms 2644 KB Output is correct
4 Correct 3 ms 2644 KB Output is correct
5 Correct 2 ms 2644 KB Output is correct
6 Correct 1 ms 2644 KB Output is correct
7 Correct 2 ms 2644 KB Output is correct
8 Correct 1 ms 2644 KB Output is correct
9 Correct 2 ms 2644 KB Output is correct
10 Correct 2 ms 2644 KB Output is correct
11 Correct 3 ms 2644 KB Output is correct
12 Correct 2 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 1 ms 2644 KB Output is correct
16 Correct 2 ms 2644 KB Output is correct

Subtask #3
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 62 ms 18580 KB Output is correct
2 Correct 62 ms 18320 KB Output is correct
3 Correct 67 ms 18652 KB Output is correct

Subtask #4
40.0 / 40.0

# Verdict Execution time Memory Grader output
1 Correct 50 ms 18564 KB Output is correct
2 Correct 44 ms 18356 KB Output is correct
3 Correct 48 ms 18636 KB Output is correct
4 Correct 44 ms 7204 KB Output is correct
5 Correct 43 ms 7636 KB Output is correct
6 Correct 42 ms 7712 KB Output is correct
7 Correct 2 ms 2632 KB Output is correct
8 Correct 17 ms 4436 KB Output is correct
9 Correct 73 ms 7764 KB Output is correct
10 Correct 65 ms 7772 KB Output is correct
11 Correct 48 ms 8524 KB Output is correct
12 Correct 46 ms 8780 KB Output is correct
13 Correct 43 ms 7384 KB Output is correct
14 Correct 42 ms 7736 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 1 ms 2644 KB Output is correct
4 Correct 3 ms 2644 KB Output is correct
5 Correct 2 ms 2644 KB Output is correct
6 Correct 1 ms 2644 KB Output is correct
7 Correct 2 ms 2644 KB Output is correct
8 Correct 1 ms 2644 KB Output is correct
9 Correct 2 ms 2644 KB Output is correct
10 Correct 2 ms 2644 KB Output is correct
11 Correct 3 ms 2644 KB Output is correct
12 Correct 2 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 1 ms 2644 KB Output is correct
16 Correct 2 ms 2644 KB Output is correct
17 Correct 62 ms 18580 KB Output is correct
18 Correct 62 ms 18320 KB Output is correct
19 Correct 67 ms 18652 KB Output is correct
20 Correct 50 ms 18564 KB Output is correct
21 Correct 44 ms 18356 KB Output is correct
22 Correct 48 ms 18636 KB Output is correct
23 Correct 44 ms 7204 KB Output is correct
24 Correct 43 ms 7636 KB Output is correct
25 Correct 42 ms 7712 KB Output is correct
26 Correct 2 ms 2632 KB Output is correct
27 Correct 17 ms 4436 KB Output is correct
28 Correct 73 ms 7764 KB Output is correct
29 Correct 65 ms 7772 KB Output is correct
30 Correct 48 ms 8524 KB Output is correct
31 Correct 46 ms 8780 KB Output is correct
32 Correct 43 ms 7384 KB Output is correct
33 Correct 42 ms 7736 KB Output is correct
34 Correct 1 ms 2644 KB Output is correct
35 Correct 2 ms 2644 KB Output is correct
36 Correct 2 ms 2644 KB Output is correct
37 Correct 1 ms 2644 KB Output is correct
38 Correct 2 ms 2644 KB Output is correct
39 Correct 2 ms 2564 KB Output is correct
40 Correct 2 ms 2644 KB Output is correct
41 Correct 2 ms 2644 KB Output is correct
42 Correct 2 ms 2644 KB Output is correct
43 Correct 2 ms 2644 KB Output is correct
44 Correct 2 ms 2644 KB Output is correct
45 Correct 46 ms 18508 KB Output is correct
46 Correct 44 ms 18308 KB Output is correct
47 Correct 56 ms 18608 KB Output is correct
48 Correct 60 ms 7208 KB Output is correct
49 Correct 62 ms 7628 KB Output is correct
50 Correct 46 ms 7740 KB Output is correct
51 Correct 1 ms 2644 KB Output is correct
52 Correct 14 ms 4436 KB Output is correct
53 Correct 52 ms 7764 KB Output is correct
54 Correct 50 ms 7860 KB Output is correct
55 Correct 56 ms 8468 KB Output is correct
56 Correct 82 ms 8832 KB Output is correct
57 Correct 44 ms 7412 KB Output is correct
58 Correct 52 ms 7736 KB Output is correct
59 Correct 13 ms 4292 KB Output is correct
60 Correct 51 ms 7264 KB Output is correct
61 Correct 44 ms 7736 KB Output is correct
62 Correct 44 ms 7848 KB Output is correct
63 Correct 60 ms 7808 KB Output is correct
64 Correct 77 ms 7884 KB Output is correct
65 Correct 43 ms 8204 KB Output is correct
66 Correct 41 ms 8188 KB Output is correct
67 Correct 33 ms 8140 KB Output is correct
68 Correct 34 ms 8048 KB Output is correct
69 Correct 36 ms 8132 KB Output is correct
70 Correct 32 ms 8096 KB Output is correct