Submission #908769

#	Submission time	Handle	Problem	Language	Result	Execution time	Memory
908769	2024-01-16T19:57:06 Z	dsyz	The Xana coup (BOI21_xanadu)	C++17	100 / 100	61 ms	18544 KB

xanadu

#include <bits/stdc++.h>
using namespace std;
using ll = long long;
#define MAXN (100005)
ll N;
vector<ll> v[MAXN];
ll dp[MAXN][2][2]; //index, press node x's button, final state of node x
bool initial[MAXN];
void dfs(ll x,ll p){
	if(initial[x]){
		dp[x][1][0] = 1;
		dp[x][0][1] = 0;
	}else{
		dp[x][1][1] = 1;
		dp[x][0][0] = 0;
	}
	for(auto u : v[x]){
		if(u != p){
			dfs(u,x);
			ll a = dp[x][0][0], b = dp[x][0][1], c = dp[x][1][0], d = dp[x][1][1];
			dp[x][0][0] = min(a + dp[u][0][0],b + dp[u][1][0]);
			dp[x][0][1] = min(b + dp[u][0][0],a + dp[u][1][0]);
			dp[x][1][0] = min(c + dp[u][0][1],d + dp[u][1][1]);
			dp[x][1][1] = min(d + dp[u][0][1],c + dp[u][1][1]);
		}
	}
}
int main() {
	ios_base::sync_with_stdio(false);cin.tie(0);
	cin>>N;
	for(ll i = 0;i < N - 1;i++){
		ll a,b;
		cin>>a>>b;
		a--, b--;
		v[a].push_back(b);
		v[b].push_back(a);
	}
	for(ll i = 0;i < N;i++){
		cin>>initial[i];
	}
	for(ll i = 0;i < N;i++){
		for(ll j = 0;j < 2;j++){
			for(ll k = 0;k < 2;k++){
				dp[i][j][k] = 1e9;
			}
		}
	}
	dfs(0,-1);
	ll minimum = 1e9;
	minimum = min({minimum,dp[0][0][0],dp[0][1][0]}); //note that node 0 is the root so its final state must be turned off
	if(minimum >= 1e9){
		cout<<"impossible"<<'\n';
	}else{
		cout<<minimum<<'\n';
	}
}

Subtask #1
5.0 / 5.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	2 ms	3676 KB	Output is correct
2	Correct	2 ms	3672 KB	Output is correct
3	Correct	1 ms	3676 KB	Output is correct
4	Correct	2 ms	3928 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	2 ms	3672 KB	Output is correct
3	Correct	1 ms	3676 KB	Output is correct
4	Correct	2 ms	3928 KB	Output is correct
5	Correct	2 ms	3676 KB	Output is correct
6	Correct	1 ms	3676 KB	Output is correct
7	Correct	1 ms	3676 KB	Output is correct
8	Correct	1 ms	3676 KB	Output is correct
9	Correct	2 ms	3676 KB	Output is correct
10	Correct	2 ms	3676 KB	Output is correct
11	Correct	1 ms	3676 KB	Output is correct
12	Correct	1 ms	3676 KB	Output is correct
13	Correct	2 ms	3676 KB	Output is correct
14	Correct	2 ms	3756 KB	Output is correct
15	Correct	2 ms	3676 KB	Output is correct
16	Correct	2 ms	3676 KB	Output is correct

Subtask #3
10.0 / 10.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	38 ms	18004 KB	Output is correct
2	Correct	42 ms	18004 KB	Output is correct
3	Correct	53 ms	18544 KB	Output is correct

Subtask #4
40.0 / 40.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	37 ms	18004 KB	Output is correct
2	Correct	43 ms	18000 KB	Output is correct
3	Correct	39 ms	18256 KB	Output is correct
4	Correct	35 ms	10588 KB	Output is correct
5	Correct	37 ms	11252 KB	Output is correct
6	Correct	34 ms	11344 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	10844 KB	Output is correct
10	Correct	36 ms	11096 KB	Output is correct
11	Correct	38 ms	11484 KB	Output is correct
12	Correct	41 ms	11600 KB	Output is correct
13	Correct	43 ms	11092 KB	Output is correct
14	Correct	36 ms	11612 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	2 ms	3672 KB	Output is correct
3	Correct	1 ms	3676 KB	Output is correct
4	Correct	2 ms	3928 KB	Output is correct
5	Correct	2 ms	3676 KB	Output is correct
6	Correct	1 ms	3676 KB	Output is correct
7	Correct	1 ms	3676 KB	Output is correct
8	Correct	1 ms	3676 KB	Output is correct
9	Correct	2 ms	3676 KB	Output is correct
10	Correct	2 ms	3676 KB	Output is correct
11	Correct	1 ms	3676 KB	Output is correct
12	Correct	1 ms	3676 KB	Output is correct
13	Correct	2 ms	3676 KB	Output is correct
14	Correct	2 ms	3756 KB	Output is correct
15	Correct	2 ms	3676 KB	Output is correct
16	Correct	2 ms	3676 KB	Output is correct
17	Correct	38 ms	18004 KB	Output is correct
18	Correct	42 ms	18004 KB	Output is correct
19	Correct	53 ms	18544 KB	Output is correct
20	Correct	37 ms	18004 KB	Output is correct
21	Correct	43 ms	18000 KB	Output is correct
22	Correct	39 ms	18256 KB	Output is correct
23	Correct	35 ms	10588 KB	Output is correct
24	Correct	37 ms	11252 KB	Output is correct
25	Correct	34 ms	11344 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	10844 KB	Output is correct
29	Correct	36 ms	11096 KB	Output is correct
30	Correct	38 ms	11484 KB	Output is correct
31	Correct	41 ms	11600 KB	Output is correct
32	Correct	43 ms	11092 KB	Output is correct
33	Correct	36 ms	11612 KB	Output is correct
34	Correct	2 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	2 ms	3676 KB	Output is correct
38	Correct	1 ms	3676 KB	Output is correct
39	Correct	2 ms	3676 KB	Output is correct
40	Correct	1 ms	3932 KB	Output is correct
41	Correct	1 ms	3676 KB	Output is correct
42	Correct	1 ms	3676 KB	Output is correct
43	Correct	1 ms	3676 KB	Output is correct
44	Correct	1 ms	3676 KB	Output is correct
45	Correct	40 ms	18012 KB	Output is correct
46	Correct	37 ms	18012 KB	Output is correct
47	Correct	44 ms	18308 KB	Output is correct
48	Correct	34 ms	10576 KB	Output is correct
49	Correct	33 ms	11260 KB	Output is correct
50	Correct	34 ms	11344 KB	Output is correct
51	Correct	2 ms	3804 KB	Output is correct
52	Correct	13 ms	7516 KB	Output is correct
53	Correct	33 ms	10976 KB	Output is correct
54	Correct	38 ms	11100 KB	Output is correct
55	Correct	33 ms	11268 KB	Output is correct
56	Correct	35 ms	11480 KB	Output is correct
57	Correct	31 ms	11092 KB	Output is correct
58	Correct	34 ms	11484 KB	Output is correct
59	Correct	12 ms	7768 KB	Output is correct
60	Correct	30 ms	10332 KB	Output is correct
61	Correct	33 ms	10832 KB	Output is correct
62	Correct	38 ms	10832 KB	Output is correct
63	Correct	39 ms	11072 KB	Output is correct
64	Correct	61 ms	10832 KB	Output is correct
65	Correct	42 ms	11548 KB	Output is correct
66	Correct	30 ms	11344 KB	Output is correct
67	Correct	27 ms	11152 KB	Output is correct
68	Correct	36 ms	11164 KB	Output is correct
69	Correct	27 ms	11100 KB	Output is correct
70	Correct	27 ms	11204 KB	Output is correct

Submission #908769

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