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Submission #866946

# Submission time Handle Problem Language Result Execution time Memory
866946 2023-10-27T12:46:21 Z Mizo_Compiler The Xana coup (BOI21_xanadu) C++17
100 / 100
 55 ms 21600 KB 
#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef double ld;
#define pb push_back
#define sz(x) int(x.size())
#define all(x) x.begin(),x.end()
#define F first
#define S second
const int N = 1e5+5;
int n, a[N];
vector<int> adj[N];
ll dp[N][2][2];

ll sol(int u, int pv, int nv, int par) {
	ll &ret = dp[u][pv][nv];
	if (~ret)return ret;
	int cur = (a[u] ^ pv ^ nv);
	if (!cur) {
		ll mn = n+1;
		bool c = 0;
		ret = nv;
		for (auto &v : adj[u]) {
			if (v == par)continue;
			ll f = sol(v, nv, 0, u), s = sol(v, nv, 1, u);
			mn = min(mn, abs(f-s));
			ret += min(f, s);
			if (s < f)c ^= 1;
		}
		if (c)ret += mn;
		return ret;
	} else {
		if (sz(adj[u]) == 1 && u)return ret = n+1;
		ll mn = n+1;
		bool c = 0;
		ret = nv;
		for (auto &v : adj[u]) {
			if (v == par)continue;
			ll f = sol(v, nv, 0, u), s = sol(v, nv, 1, u);
			mn = min(mn, abs(f-s));
			ret += min(f, s);
			if (s < f)c ^= 1;
		}
		if (!c)ret += mn;
		return ret;
	}
}

int main () {
	ios::sync_with_stdio(false);
	cin.tie(nullptr);
	cin >> n;
	for (int i = 0; i+1 < n; i++) {
		int u, v;
		cin >> u >> v;
		--u, --v;
		adj[u].pb(v);
		adj[v].pb(u);
	}
	for (int i = 0; i < n; i++) {
		cin >> a[i];
		for (int j = 0; j < 2; j++) {
			for (int k = 0; k < 2; k++) {
				dp[i][j][k] = -1;
			}
		}
	}
	ll x = min(sol(0, 0, 1, 0), sol(0, 0, 0, 0));
	if (x > n) {
		cout << "impossible\n";
		return 0;
	}
	cout << x << "\n";
}

Subtask #1
5.0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 3676 KB Output is correct
2 Correct 1 ms 3676 KB Output is correct
3 Correct 1 ms 3676 KB Output is correct
4 Correct 1 ms 3676 KB Output is correct
5 Correct 1 ms 3676 KB Output is correct

Subtask #2
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 3676 KB Output is correct
2 Correct 1 ms 3676 KB Output is correct
3 Correct 1 ms 3676 KB Output is correct
4 Correct 1 ms 3676 KB Output is correct
5 Correct 1 ms 3676 KB Output is correct
6 Correct 2 ms 3684 KB Output is correct
7 Correct 1 ms 3676 KB Output is correct
8 Correct 1 ms 3676 KB Output is correct
9 Correct 1 ms 3676 KB Output is correct
10 Correct 1 ms 3676 KB Output is correct
11 Correct 1 ms 3676 KB Output is correct
12 Correct 2 ms 3676 KB Output is correct
13 Correct 1 ms 3676 KB Output is correct
14 Correct 1 ms 3676 KB Output is correct
15 Correct 1 ms 3676 KB Output is correct
16 Correct 1 ms 3676 KB Output is correct

Subtask #3
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 46 ms 21596 KB Output is correct
2 Correct 41 ms 21468 KB Output is correct
3 Correct 50 ms 21600 KB Output is correct

Subtask #4
40.0 / 40.0

# Verdict Execution time Memory Grader output
1 Correct 53 ms 21584 KB Output is correct
2 Correct 46 ms 21392 KB Output is correct
3 Correct 42 ms 21584 KB Output is correct
4 Correct 41 ms 10092 KB Output is correct
5 Correct 38 ms 10584 KB Output is correct
6 Correct 47 ms 10844 KB Output is correct
7 Correct 1 ms 3684 KB Output is correct
8 Correct 14 ms 7512 KB Output is correct
9 Correct 38 ms 10592 KB Output is correct
10 Correct 38 ms 10848 KB Output is correct
11 Correct 41 ms 11360 KB Output is correct
12 Correct 38 ms 11696 KB Output is correct
13 Correct 36 ms 10320 KB Output is correct
14 Correct 43 ms 10780 KB Output is correct

Subtask #5
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 3676 KB Output is correct
2 Correct 1 ms 3676 KB Output is correct
3 Correct 1 ms 3676 KB Output is correct
4 Correct 1 ms 3676 KB Output is correct
5 Correct 1 ms 3676 KB Output is correct
6 Correct 2 ms 3684 KB Output is correct
7 Correct 1 ms 3676 KB Output is correct
8 Correct 1 ms 3676 KB Output is correct
9 Correct 1 ms 3676 KB Output is correct
10 Correct 1 ms 3676 KB Output is correct
11 Correct 1 ms 3676 KB Output is correct
12 Correct 2 ms 3676 KB Output is correct
13 Correct 1 ms 3676 KB Output is correct
14 Correct 1 ms 3676 KB Output is correct
15 Correct 1 ms 3676 KB Output is correct
16 Correct 1 ms 3676 KB Output is correct
17 Correct 46 ms 21596 KB Output is correct
18 Correct 41 ms 21468 KB Output is correct
19 Correct 50 ms 21600 KB Output is correct
20 Correct 53 ms 21584 KB Output is correct
21 Correct 46 ms 21392 KB Output is correct
22 Correct 42 ms 21584 KB Output is correct
23 Correct 41 ms 10092 KB Output is correct
24 Correct 38 ms 10584 KB Output is correct
25 Correct 47 ms 10844 KB Output is correct
26 Correct 1 ms 3684 KB Output is correct
27 Correct 14 ms 7512 KB Output is correct
28 Correct 38 ms 10592 KB Output is correct
29 Correct 38 ms 10848 KB Output is correct
30 Correct 41 ms 11360 KB Output is correct
31 Correct 38 ms 11696 KB Output is correct
32 Correct 36 ms 10320 KB Output is correct
33 Correct 43 ms 10780 KB Output is correct
34 Correct 1 ms 3676 KB Output is correct
35 Correct 1 ms 3676 KB Output is correct
36 Correct 1 ms 3676 KB Output is correct
37 Correct 1 ms 3672 KB Output is correct
38 Correct 1 ms 3676 KB Output is correct
39 Correct 1 ms 3672 KB Output is correct
40 Correct 1 ms 3676 KB Output is correct
41 Correct 1 ms 3676 KB Output is correct
42 Correct 2 ms 3672 KB Output is correct
43 Correct 1 ms 3676 KB Output is correct
44 Correct 1 ms 3676 KB Output is correct
45 Correct 52 ms 21560 KB Output is correct
46 Correct 43 ms 21436 KB Output is correct
47 Correct 43 ms 21572 KB Output is correct
48 Correct 39 ms 10064 KB Output is correct
49 Correct 53 ms 10688 KB Output is correct
50 Correct 38 ms 10580 KB Output is correct
51 Correct 1 ms 3672 KB Output is correct
52 Correct 13 ms 7516 KB Output is correct
53 Correct 36 ms 10804 KB Output is correct
54 Correct 55 ms 10836 KB Output is correct
55 Correct 38 ms 11612 KB Output is correct
56 Correct 39 ms 11704 KB Output is correct
57 Correct 33 ms 10332 KB Output is correct
58 Correct 35 ms 10740 KB Output is correct
59 Correct 13 ms 7512 KB Output is correct
60 Correct 36 ms 10324 KB Output is correct
61 Correct 36 ms 10580 KB Output is correct
62 Correct 37 ms 10852 KB Output is correct
63 Correct 41 ms 10844 KB Output is correct
64 Correct 41 ms 10844 KB Output is correct
65 Correct 35 ms 11356 KB Output is correct
66 Correct 34 ms 11348 KB Output is correct
67 Correct 30 ms 11208 KB Output is correct
68 Correct 31 ms 11216 KB Output is correct
69 Correct 32 ms 10956 KB Output is correct
70 Correct 31 ms 10956 KB Output is correct