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Submission #872345

# Submission time Handle Problem Language Result Execution time Memory
872345 2023-11-12T23:04:54 Z Cyber_Wolf The Xana coup (BOI21_xanadu) C++17
100 / 100
 118 ms 45676 KB 
#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
#pragma GCC optimize("Ofast")

using namespace std;
using namespace __gnu_pbds;

#define lg long long
#define ordered_set	tree<int, null_type, less<int>, rb_tree_tag, tree_order_statistics_node_update>
#define fastio ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0);

const lg N = 1e5+5;

vector<lg> adj[N];
lg c[N];
lg dp[N][2][2];
lg n;

lg dfs(lg src, lg ef, lg cur, lg par = - 1)
{
	auto&ret = dp[src][ef][cur];
	if(~ret)	return ret;
	ret = n+2;
	lg sz = adj[src].size();
	vector<vector<lg>> dp2(sz+1, vector<lg> (2, n+2));
	dp2[0][0] = 0;
	for(int i = 1; i <= sz; i++)
	{
		if(adj[src][i-1] == par)
		{
			dp2[i][0] = dp2[i-1][0];
			dp2[i][1] = dp2[i-1][1];
			continue;
		}
		dp2[i][0] = min(dp2[i-1][0]+dfs(adj[src][i-1], 0, ef^c[adj[src][i-1]], src), dp2[i-1][1]+dfs(adj[src][i-1], 1, ef^1^c[adj[src][i-1]], src)+1);
		dp2[i][1] = min(dp2[i-1][1]+dfs(adj[src][i-1], 0, ef^c[adj[src][i-1]], src), dp2[i-1][0]+dfs(adj[src][i-1], 1, ef^1^c[adj[src][i-1]], src)+1);
	}
	ret = dp2[sz][cur];
	return ret;
}

int main()
{
	fastio;
	cin >> n;
	for(int i = 1; i < n; i++)
	{
		lg u, v;
		cin >> u >> v;
		adj[u].push_back(v);
		adj[v].push_back(u);
	}
	for(int i = 1; i <= n; i++)	cin >> c[i];
	memset(dp, -1, sizeof(dp));
	lg ans = min(dfs(1, 0, c[1]), dfs(1, 1, c[1]^1)+1);
	if(ans > n)
	{
		cout << "impossible\n";
		return 0;
	}
	cout << ans << '\n';

    return 0;
}

Subtask #1
5.0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 6488 KB Output is correct
2 Correct 2 ms 6492 KB Output is correct
3 Correct 2 ms 6492 KB Output is correct
4 Correct 2 ms 6492 KB Output is correct
5 Correct 3 ms 6696 KB Output is correct

Subtask #2
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 6488 KB Output is correct
2 Correct 2 ms 6492 KB Output is correct
3 Correct 2 ms 6492 KB Output is correct
4 Correct 2 ms 6492 KB Output is correct
5 Correct 3 ms 6696 KB Output is correct
6 Correct 2 ms 6488 KB Output is correct
7 Correct 2 ms 6492 KB Output is correct
8 Correct 2 ms 6492 KB Output is correct
9 Correct 2 ms 6488 KB Output is correct
10 Correct 1 ms 6488 KB Output is correct
11 Correct 2 ms 6492 KB Output is correct
12 Correct 2 ms 6492 KB Output is correct
13 Correct 2 ms 6492 KB Output is correct
14 Correct 2 ms 6492 KB Output is correct
15 Correct 2 ms 6488 KB Output is correct
16 Correct 2 ms 6492 KB Output is correct

Subtask #3
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 107 ms 45676 KB Output is correct
2 Correct 93 ms 44880 KB Output is correct
3 Correct 97 ms 45616 KB Output is correct

Subtask #4
40.0 / 40.0

# Verdict Execution time Memory Grader output
1 Correct 117 ms 45392 KB Output is correct
2 Correct 102 ms 45272 KB Output is correct
3 Correct 96 ms 45388 KB Output is correct
4 Correct 65 ms 11488 KB Output is correct
5 Correct 83 ms 11968 KB Output is correct
6 Correct 78 ms 11904 KB Output is correct
7 Correct 2 ms 6744 KB Output is correct
8 Correct 26 ms 8508 KB Output is correct
9 Correct 86 ms 11856 KB Output is correct
10 Correct 107 ms 11824 KB Output is correct
11 Correct 103 ms 14836 KB Output is correct
12 Correct 86 ms 15380 KB Output is correct
13 Correct 74 ms 12008 KB Output is correct
14 Correct 72 ms 12300 KB Output is correct

Subtask #5
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 6488 KB Output is correct
2 Correct 2 ms 6492 KB Output is correct
3 Correct 2 ms 6492 KB Output is correct
4 Correct 2 ms 6492 KB Output is correct
5 Correct 3 ms 6696 KB Output is correct
6 Correct 2 ms 6488 KB Output is correct
7 Correct 2 ms 6492 KB Output is correct
8 Correct 2 ms 6492 KB Output is correct
9 Correct 2 ms 6488 KB Output is correct
10 Correct 1 ms 6488 KB Output is correct
11 Correct 2 ms 6492 KB Output is correct
12 Correct 2 ms 6492 KB Output is correct
13 Correct 2 ms 6492 KB Output is correct
14 Correct 2 ms 6492 KB Output is correct
15 Correct 2 ms 6488 KB Output is correct
16 Correct 2 ms 6492 KB Output is correct
17 Correct 107 ms 45676 KB Output is correct
18 Correct 93 ms 44880 KB Output is correct
19 Correct 97 ms 45616 KB Output is correct
20 Correct 117 ms 45392 KB Output is correct
21 Correct 102 ms 45272 KB Output is correct
22 Correct 96 ms 45388 KB Output is correct
23 Correct 65 ms 11488 KB Output is correct
24 Correct 83 ms 11968 KB Output is correct
25 Correct 78 ms 11904 KB Output is correct
26 Correct 2 ms 6744 KB Output is correct
27 Correct 26 ms 8508 KB Output is correct
28 Correct 86 ms 11856 KB Output is correct
29 Correct 107 ms 11824 KB Output is correct
30 Correct 103 ms 14836 KB Output is correct
31 Correct 86 ms 15380 KB Output is correct
32 Correct 74 ms 12008 KB Output is correct
33 Correct 72 ms 12300 KB Output is correct
34 Correct 2 ms 6752 KB Output is correct
35 Correct 2 ms 6492 KB Output is correct
36 Correct 2 ms 6492 KB Output is correct
37 Correct 2 ms 6492 KB Output is correct
38 Correct 2 ms 6492 KB Output is correct
39 Correct 2 ms 6492 KB Output is correct
40 Correct 2 ms 6492 KB Output is correct
41 Correct 2 ms 6492 KB Output is correct
42 Correct 2 ms 6492 KB Output is correct
43 Correct 2 ms 6492 KB Output is correct
44 Correct 2 ms 6492 KB Output is correct
45 Correct 101 ms 45392 KB Output is correct
46 Correct 98 ms 44940 KB Output is correct
47 Correct 118 ms 45396 KB Output is correct
48 Correct 67 ms 11348 KB Output is correct
49 Correct 82 ms 11856 KB Output is correct
50 Correct 77 ms 11856 KB Output is correct
51 Correct 2 ms 6744 KB Output is correct
52 Correct 26 ms 8532 KB Output is correct
53 Correct 112 ms 11976 KB Output is correct
54 Correct 80 ms 12036 KB Output is correct
55 Correct 79 ms 14840 KB Output is correct
56 Correct 85 ms 15188 KB Output is correct
57 Correct 83 ms 12012 KB Output is correct
58 Correct 82 ms 12212 KB Output is correct
59 Correct 25 ms 8280 KB Output is correct
60 Correct 71 ms 11380 KB Output is correct
61 Correct 75 ms 11824 KB Output is correct
62 Correct 75 ms 11992 KB Output is correct
63 Correct 83 ms 12024 KB Output is correct
64 Correct 76 ms 11844 KB Output is correct
65 Correct 93 ms 12376 KB Output is correct
66 Correct 81 ms 12116 KB Output is correct
67 Correct 79 ms 17352 KB Output is correct
68 Correct 79 ms 17316 KB Output is correct
69 Correct 87 ms 17352 KB Output is correct
70 Correct 77 ms 17356 KB Output is correct