Submission #904854

#	Submission time	Handle	Problem	Language	Result	Execution time	Memory
904854	2024-01-12T10:31:28 Z	vjudge1	The Xana coup (BOI21_xanadu)	C++17	100 / 100	88 ms	26232 KB

xanadu

#include <iostream>
#include <vector>

#define endl '\n'
#define pb push_back
#define ll long long

using namespace std;

const int MAXN = 1e5+100;
const ll INF = 1e6+109;

int n;
bool a[MAXN], used[MAXN];
vector<int> adj[MAXN];

ll dp[MAXN][2][2];

ll min(ll a, ll b){
	return (a < b)? a : b;
}

void dfs(int v){
	used[v] = 1;


	ll cdp[2][2];
	ll tmp[2][2];

	bool flg = true;

	for(int u : adj[v]){
		if(used[u]) continue;

		dfs(u);

		if(flg){
			for(int i=0; i<2; i++){
				for(int j=0; j<2; j++){
					cdp[i][j] = dp[u][i][j];
					tmp[i][j] = INF;
				}
			}

		}
		else{
			for(int i=0; i<2; i++){
				tmp[i][0] = min(tmp[i][0], cdp[i][0] + dp[u][i][0]);
				tmp[i][0] = min(tmp[i][0], cdp[i][1] + dp[u][i][1]);
				tmp[i][1] = min(tmp[i][1], cdp[i][0] + dp[u][i][1]);
				tmp[i][1] = min(tmp[i][1], cdp[i][1] + dp[u][i][0]);
					
			/*
			if(v == 1){
				cout << "A: "<< endl;
				for(int i=0; i<2; i++){
					for(int j=0; j<2; j++) cout << tmp[i][j] << ' ';
					cout << endl;
				}
			}
			*/

			}


		}

		for(int i=0; i<2; i++){
			for(int j=0; j<2; j++){
				if(!flg) cdp[i][j] = tmp[i][j];
				tmp[i][j] = INF;
			}
		}

		flg = false;
	}

	for(int i=0; i<2; i++){
		for(int j=0; j<2; j++){
			if(a[v]) dp[v][i][j] = cdp[j][i^j^1] + j;
			else dp[v][i][j] = cdp[j][i^j] + j;
			
		}
	}

	if(flg){
		if(a[v]){
			dp[v][1][0] = 0;
			dp[v][0][1] = 1;
			dp[v][1][1] = INF;
			dp[v][0][0] = INF;
		}
		else{
			dp[v][0][0] = 0;
			dp[v][1][1] = 1;
			dp[v][1][0] = INF;
			dp[v][0][1] = INF;
		}
	}
			
}	


int main(){
	ios::sync_with_stdio(0);cin.tie(0);
	cin >> n;

	for(int i=1; i<n; i++){
		int x, y;

		cin >> x >> y;
		x--;y--;

		adj[x].pb(y);
		adj[y].pb(x);
	}

	for(int i=0; i<n; i++) cin >> a[i];

	dfs(0);

	if(min(dp[0][0][0], dp[0][0][1]) >= INF) cout << "impossible" << endl;
	else cout << min(dp[0][0][0], dp[0][0][1]) << endl;


	return 0;
}

Subtask #1
5.0 / 5.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	2 ms	3676 KB	Output is correct
2	Correct	1 ms	3712 KB	Output is correct
3	Correct	3 ms	3676 KB	Output is correct
4	Correct	1 ms	3712 KB	Output is correct
5	Correct	2 ms	3676 KB	Output is correct

Subtask #2
15.0 / 15.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	2 ms	3676 KB	Output is correct
2	Correct	1 ms	3712 KB	Output is correct
3	Correct	3 ms	3676 KB	Output is correct
4	Correct	1 ms	3712 KB	Output is correct
5	Correct	2 ms	3676 KB	Output is correct
6	Correct	2 ms	3468 KB	Output is correct
7	Correct	2 ms	3676 KB	Output is correct
8	Correct	2 ms	3724 KB	Output is correct
9	Correct	2 ms	3708 KB	Output is correct
10	Correct	2 ms	3932 KB	Output is correct
11	Correct	2 ms	3720 KB	Output is correct
12	Correct	2 ms	3676 KB	Output is correct
13	Correct	2 ms	3676 KB	Output is correct
14	Correct	2 ms	3676 KB	Output is correct
15	Correct	2 ms	3676 KB	Output is correct
16	Correct	2 ms	3508 KB	Output is correct

Subtask #3
10.0 / 10.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	62 ms	26008 KB	Output is correct
2	Correct	70 ms	25708 KB	Output is correct
3	Correct	88 ms	26076 KB	Output is correct

Subtask #4
40.0 / 40.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	75 ms	26144 KB	Output is correct
2	Correct	62 ms	25724 KB	Output is correct
3	Correct	65 ms	26232 KB	Output is correct
4	Correct	51 ms	10068 KB	Output is correct
5	Correct	56 ms	10368 KB	Output is correct
6	Correct	61 ms	10536 KB	Output is correct
7	Correct	2 ms	3676 KB	Output is correct
8	Correct	12 ms	7516 KB	Output is correct
9	Correct	34 ms	10588 KB	Output is correct
10	Correct	73 ms	10580 KB	Output is correct
11	Correct	38 ms	11860 KB	Output is correct
12	Correct	51 ms	11860 KB	Output is correct
13	Correct	31 ms	10332 KB	Output is correct
14	Correct	32 ms	10588 KB	Output is correct

Subtask #5
30.0 / 30.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	2 ms	3676 KB	Output is correct
2	Correct	1 ms	3712 KB	Output is correct
3	Correct	3 ms	3676 KB	Output is correct
4	Correct	1 ms	3712 KB	Output is correct
5	Correct	2 ms	3676 KB	Output is correct
6	Correct	2 ms	3468 KB	Output is correct
7	Correct	2 ms	3676 KB	Output is correct
8	Correct	2 ms	3724 KB	Output is correct
9	Correct	2 ms	3708 KB	Output is correct
10	Correct	2 ms	3932 KB	Output is correct
11	Correct	2 ms	3720 KB	Output is correct
12	Correct	2 ms	3676 KB	Output is correct
13	Correct	2 ms	3676 KB	Output is correct
14	Correct	2 ms	3676 KB	Output is correct
15	Correct	2 ms	3676 KB	Output is correct
16	Correct	2 ms	3508 KB	Output is correct
17	Correct	62 ms	26008 KB	Output is correct
18	Correct	70 ms	25708 KB	Output is correct
19	Correct	88 ms	26076 KB	Output is correct
20	Correct	75 ms	26144 KB	Output is correct
21	Correct	62 ms	25724 KB	Output is correct
22	Correct	65 ms	26232 KB	Output is correct
23	Correct	51 ms	10068 KB	Output is correct
24	Correct	56 ms	10368 KB	Output is correct
25	Correct	61 ms	10536 KB	Output is correct
26	Correct	2 ms	3676 KB	Output is correct
27	Correct	12 ms	7516 KB	Output is correct
28	Correct	34 ms	10588 KB	Output is correct
29	Correct	73 ms	10580 KB	Output is correct
30	Correct	38 ms	11860 KB	Output is correct
31	Correct	51 ms	11860 KB	Output is correct
32	Correct	31 ms	10332 KB	Output is correct
33	Correct	32 ms	10588 KB	Output is correct
34	Correct	2 ms	3676 KB	Output is correct
35	Correct	2 ms	3676 KB	Output is correct
36	Correct	2 ms	3676 KB	Output is correct
37	Correct	2 ms	3676 KB	Output is correct
38	Correct	2 ms	3932 KB	Output is correct
39	Correct	2 ms	3676 KB	Output is correct
40	Correct	2 ms	3676 KB	Output is correct
41	Correct	2 ms	3932 KB	Output is correct
42	Correct	2 ms	3676 KB	Output is correct
43	Correct	2 ms	3676 KB	Output is correct
44	Correct	2 ms	3676 KB	Output is correct
45	Correct	65 ms	26116 KB	Output is correct
46	Correct	48 ms	25860 KB	Output is correct
47	Correct	56 ms	26196 KB	Output is correct
48	Correct	39 ms	10060 KB	Output is correct
49	Correct	46 ms	10324 KB	Output is correct
50	Correct	51 ms	10580 KB	Output is correct
51	Correct	2 ms	3676 KB	Output is correct
52	Correct	16 ms	7516 KB	Output is correct
53	Correct	71 ms	10580 KB	Output is correct
54	Correct	35 ms	10568 KB	Output is correct
55	Correct	39 ms	11604 KB	Output is correct
56	Correct	36 ms	11860 KB	Output is correct
57	Correct	51 ms	10444 KB	Output is correct
58	Correct	32 ms	10588 KB	Output is correct
59	Correct	13 ms	7516 KB	Output is correct
60	Correct	42 ms	10188 KB	Output is correct
61	Correct	41 ms	10608 KB	Output is correct
62	Correct	45 ms	10748 KB	Output is correct
63	Correct	60 ms	10580 KB	Output is correct
64	Correct	40 ms	10580 KB	Output is correct
65	Correct	43 ms	11100 KB	Output is correct
66	Correct	32 ms	10984 KB	Output is correct
67	Correct	31 ms	10956 KB	Output is correct
68	Correct	43 ms	10952 KB	Output is correct
69	Correct	29 ms	10856 KB	Output is correct
70	Correct	34 ms	10956 KB	Output is correct

Submission #904854

Compilation message

Subtask #1 5.0 / 5.0

Subtask #2 15.0 / 15.0

Subtask #3 10.0 / 10.0

Subtask #4 40.0 / 40.0

Subtask #5 30.0 / 30.0

Subtask #1
5.0 / 5.0

Subtask #2
15.0 / 15.0

Subtask #3
10.0 / 10.0

Subtask #4
40.0 / 40.0

Subtask #5
30.0 / 30.0