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Submission #759039

# Submission time Handle Problem Language Result Execution time Memory
759039 2023-06-15T17:16:17 Z gnu The Xana coup (BOI21_xanadu) C++14
100 / 100
 171 ms 33460 KB 
#include <iostream>
#include <vector>
using namespace std;
using ll = long long;
vector<vector<vector<ll>>> dp;
vector<int> state;
void dfs(int u, int p, vector<vector<int>>& gp)
{
	ll sum1 = 0, cnt1 = 0, mn1 = 1e18, sum2 = 0, cnt2 = 0, mn2 = 1e18;
	for (int v : gp[u]) {
		if (v == p) continue;
 
		dfs(v, u, gp);
		if (dp[v][1][0] < dp[v][0][0]) {
			sum1 += dp[v][1][0];
			++cnt1;
		}
		else {
			sum1 += dp[v][0][0];
		}
		mn1 = min(mn1, abs(dp[v][1][0] - dp[v][0][0]));
		if (dp[v][1][1] < dp[v][0][1]) {
			sum2 += dp[v][1][1];
			++cnt2;
		}
		else {
			sum2 += dp[v][0][1];
		}
		mn2 = min(mn2, abs(dp[v][1][1] - dp[v][0][1]));
 
	}
	if (gp[u].size() == 1 && u != 0) {
		if (state[u]) {
			dp[u][1][0] = 1;
			dp[u][0][0] = 1e18;
			dp[u][1][1] = 1e18;
			dp[u][0][1] = 0;
		}
		else {
			dp[u][1][0] = 1e18;
			dp[u][0][0] = 0;
			dp[u][1][1] = 1;
			dp[u][0][1] = 1e18;
		}
		return;
	}
	if (((cnt1 & 1) && state[u]) || (!(cnt1 & 1) && !state[u])) {
		dp[u][0][0] = sum1;
	}
	else {
		dp[u][0][0] = sum1 + mn1;
	}
	state[u] = !state[u];
	if (((cnt2 & 1) && state[u]) || (!(cnt2 & 1) && !state[u])) {
		dp[u][1][0] = sum2+1;
	}
	else {
		dp[u][1][0] = sum2 + mn2+1;
	}
 
 
	if (((cnt1 & 1) && state[u]) || (!(cnt1 & 1) && !state[u])) {
		dp[u][0][1] = sum1;
	}
	else {
		dp[u][0][1] = sum1 + mn1;
	}
 
	state[u] = !state[u];
	if (((cnt2 & 1) && state[u]) || (!(cnt2 & 1) && !state[u])) {
		dp[u][1][1] = sum2+1;
	}
	else {
		dp[u][1][1] = sum2 + mn2+1;
	}
    dp[u][0][0] = min(dp[u][0][0], (long long) 1e18);
    dp[u][1][0] = min(dp[u][1][0], (long long) 1e18);
    dp[u][1][1] = min(dp[u][1][1], (long long) 1e18);
    dp[u][0][1] = min(dp[u][0][1], (long long) 1e18);
 
}
 
void solve()
{
	int n; cin >> n;
	vector<vector<int>> gp(n);
	state = vector<int>(n);
	dp = vector<vector<vector<ll>>>(n, vector<vector<ll>>(2, vector<ll>(2)));
	for (int i = 0; i < n - 1; ++i) {
		int u, v; cin >> u >> v; --u; --v;
		gp[u].push_back(v);
		gp[v].push_back(u);
	}
	for (int& x : state) {cin >> x;}
	dfs(0, -1, gp);
	if (min(dp[0][0][0], dp[0][1][0]) <= n) {
		cout << min(dp[0][0][0], dp[0][1][0]) << '\n';
	}
	else {
		cout <<"impossible\n";
	}
 
 
}
int main()
{
	//int t; cin >> t; while (t--)
		solve();
}

Subtask #1
5.0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 212 KB Output is correct
2 Correct 1 ms 212 KB Output is correct
3 Correct 0 ms 212 KB Output is correct
4 Correct 0 ms 212 KB Output is correct
5 Correct 0 ms 212 KB Output is correct

Subtask #2
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 212 KB Output is correct
2 Correct 1 ms 212 KB Output is correct
3 Correct 0 ms 212 KB Output is correct
4 Correct 0 ms 212 KB Output is correct
5 Correct 0 ms 212 KB Output is correct
6 Correct 0 ms 212 KB Output is correct
7 Correct 1 ms 232 KB Output is correct
8 Correct 0 ms 212 KB Output is correct
9 Correct 0 ms 212 KB Output is correct
10 Correct 0 ms 212 KB Output is correct
11 Correct 0 ms 212 KB Output is correct
12 Correct 0 ms 212 KB Output is correct
13 Correct 0 ms 212 KB Output is correct
14 Correct 0 ms 212 KB Output is correct
15 Correct 0 ms 212 KB Output is correct
16 Correct 0 ms 212 KB Output is correct

Subtask #3
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 107 ms 33308 KB Output is correct
2 Correct 93 ms 32912 KB Output is correct
3 Correct 95 ms 33460 KB Output is correct

Subtask #4
40.0 / 40.0

# Verdict Execution time Memory Grader output
1 Correct 114 ms 33268 KB Output is correct
2 Correct 122 ms 32976 KB Output is correct
3 Correct 111 ms 33432 KB Output is correct
4 Correct 98 ms 18748 KB Output is correct
5 Correct 134 ms 20576 KB Output is correct
6 Correct 122 ms 20960 KB Output is correct
7 Correct 1 ms 340 KB Output is correct
8 Correct 31 ms 7172 KB Output is correct
9 Correct 120 ms 20704 KB Output is correct
10 Correct 110 ms 21120 KB Output is correct
11 Correct 125 ms 21460 KB Output is correct
12 Correct 131 ms 22132 KB Output is correct
13 Correct 106 ms 19744 KB Output is correct
14 Correct 128 ms 21024 KB Output is correct

Subtask #5
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 212 KB Output is correct
2 Correct 1 ms 212 KB Output is correct
3 Correct 0 ms 212 KB Output is correct
4 Correct 0 ms 212 KB Output is correct
5 Correct 0 ms 212 KB Output is correct
6 Correct 0 ms 212 KB Output is correct
7 Correct 1 ms 232 KB Output is correct
8 Correct 0 ms 212 KB Output is correct
9 Correct 0 ms 212 KB Output is correct
10 Correct 0 ms 212 KB Output is correct
11 Correct 0 ms 212 KB Output is correct
12 Correct 0 ms 212 KB Output is correct
13 Correct 0 ms 212 KB Output is correct
14 Correct 0 ms 212 KB Output is correct
15 Correct 0 ms 212 KB Output is correct
16 Correct 0 ms 212 KB Output is correct
17 Correct 107 ms 33308 KB Output is correct
18 Correct 93 ms 32912 KB Output is correct
19 Correct 95 ms 33460 KB Output is correct
20 Correct 114 ms 33268 KB Output is correct
21 Correct 122 ms 32976 KB Output is correct
22 Correct 111 ms 33432 KB Output is correct
23 Correct 98 ms 18748 KB Output is correct
24 Correct 134 ms 20576 KB Output is correct
25 Correct 122 ms 20960 KB Output is correct
26 Correct 1 ms 340 KB Output is correct
27 Correct 31 ms 7172 KB Output is correct
28 Correct 120 ms 20704 KB Output is correct
29 Correct 110 ms 21120 KB Output is correct
30 Correct 125 ms 21460 KB Output is correct
31 Correct 131 ms 22132 KB Output is correct
32 Correct 106 ms 19744 KB Output is correct
33 Correct 128 ms 21024 KB Output is correct
34 Correct 1 ms 212 KB Output is correct
35 Correct 1 ms 212 KB Output is correct
36 Correct 0 ms 212 KB Output is correct
37 Correct 1 ms 212 KB Output is correct
38 Correct 0 ms 212 KB Output is correct
39 Correct 0 ms 212 KB Output is correct
40 Correct 0 ms 212 KB Output is correct
41 Correct 1 ms 212 KB Output is correct
42 Correct 0 ms 212 KB Output is correct
43 Correct 1 ms 212 KB Output is correct
44 Correct 1 ms 212 KB Output is correct
45 Correct 115 ms 33280 KB Output is correct
46 Correct 117 ms 32960 KB Output is correct
47 Correct 107 ms 33448 KB Output is correct
48 Correct 121 ms 18768 KB Output is correct
49 Correct 124 ms 20516 KB Output is correct
50 Correct 136 ms 21144 KB Output is correct
51 Correct 1 ms 340 KB Output is correct
52 Correct 43 ms 7152 KB Output is correct
53 Correct 140 ms 20708 KB Output is correct
54 Correct 113 ms 21072 KB Output is correct
55 Correct 125 ms 21512 KB Output is correct
56 Correct 171 ms 22256 KB Output is correct
57 Correct 115 ms 19688 KB Output is correct
58 Correct 115 ms 20936 KB Output is correct
59 Correct 34 ms 7204 KB Output is correct
60 Correct 108 ms 18908 KB Output is correct
61 Correct 116 ms 20676 KB Output is correct
62 Correct 129 ms 21168 KB Output is correct
63 Correct 140 ms 21104 KB Output is correct
64 Correct 170 ms 21064 KB Output is correct
65 Correct 107 ms 21508 KB Output is correct
66 Correct 109 ms 21576 KB Output is correct
67 Correct 113 ms 21408 KB Output is correct
68 Correct 108 ms 21428 KB Output is correct
69 Correct 111 ms 21344 KB Output is correct
70 Correct 136 ms 21324 KB Output is correct