#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
ll n,cur[100005];
vector <ll> al[100005];
ll vis[100005];
ll dp[100005][2][2];
void dfs(ll node){
vis[node]=1;
if (cur[node]==1){
dp[node][1][0]+=1;
dp[node][0][1]+=0;
dp[node][0][0]+=1e9;
dp[node][1][1]+=1e9;
}
else{
dp[node][1][0]+=1e9;
dp[node][0][1]+=1e9;
dp[node][0][0]+=0;
dp[node][1][1]+=1;
}
for (auto u:al[node]){
if (vis[u]!=1){
vis[u]=1;
dfs(u);
ll x=dp[node][0][0], y=dp[node][0][1];
dp[node][0][0]=min(x+dp[u][0][0],y+dp[u][1][0]);
dp[node][0][1]=min(y+dp[u][0][0],x+dp[u][1][0]);
ll a=dp[node][1][0],b=dp[node][1][1];
dp[node][1][0]=min(a+dp[u][0][1],b+dp[u][1][1]);
dp[node][1][1]=min(b+dp[u][0][1],a+dp[u][1][1]);
}
}
}
int main(){
cin>>n;
for (int i=1;i<n;i++){
ll a,b;
cin>>a>>b;
al[a].push_back(b);
al[b].push_back(a);
}
for (int i=1;i<=n;i++){
cin>>cur[i];
}
dfs(1);
ll ans=min(dp[1][0][0],dp[1][1][0]);
if (ans>n) cout<<"impossible";
else cout<<ans;
}
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
2 ms |
2644 KB |
Output is correct |
2 |
Correct |
2 ms |
2644 KB |
Output is correct |
3 |
Correct |
2 ms |
2644 KB |
Output is correct |
4 |
Correct |
2 ms |
2664 KB |
Output is correct |
5 |
Correct |
2 ms |
2644 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
2 ms |
2644 KB |
Output is correct |
2 |
Correct |
2 ms |
2644 KB |
Output is correct |
3 |
Correct |
2 ms |
2644 KB |
Output is correct |
4 |
Correct |
2 ms |
2664 KB |
Output is correct |
5 |
Correct |
2 ms |
2644 KB |
Output is correct |
6 |
Correct |
2 ms |
2660 KB |
Output is correct |
7 |
Correct |
1 ms |
2644 KB |
Output is correct |
8 |
Correct |
2 ms |
2644 KB |
Output is correct |
9 |
Correct |
1 ms |
2644 KB |
Output is correct |
10 |
Correct |
2 ms |
2644 KB |
Output is correct |
11 |
Correct |
1 ms |
2668 KB |
Output is correct |
12 |
Correct |
2 ms |
2672 KB |
Output is correct |
13 |
Correct |
1 ms |
2644 KB |
Output is correct |
14 |
Correct |
1 ms |
2644 KB |
Output is correct |
15 |
Correct |
1 ms |
2660 KB |
Output is correct |
16 |
Correct |
1 ms |
2644 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
76 ms |
17868 KB |
Output is correct |
2 |
Correct |
94 ms |
17740 KB |
Output is correct |
3 |
Correct |
74 ms |
18036 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
71 ms |
17840 KB |
Output is correct |
2 |
Correct |
73 ms |
17760 KB |
Output is correct |
3 |
Correct |
71 ms |
18028 KB |
Output is correct |
4 |
Correct |
65 ms |
11540 KB |
Output is correct |
5 |
Correct |
72 ms |
12440 KB |
Output is correct |
6 |
Correct |
79 ms |
12656 KB |
Output is correct |
7 |
Correct |
2 ms |
2644 KB |
Output is correct |
8 |
Correct |
31 ms |
5864 KB |
Output is correct |
9 |
Correct |
73 ms |
12248 KB |
Output is correct |
10 |
Correct |
93 ms |
12376 KB |
Output is correct |
11 |
Correct |
70 ms |
12508 KB |
Output is correct |
12 |
Correct |
73 ms |
12748 KB |
Output is correct |
13 |
Correct |
73 ms |
12292 KB |
Output is correct |
14 |
Correct |
99 ms |
12904 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
2 ms |
2644 KB |
Output is correct |
2 |
Correct |
2 ms |
2644 KB |
Output is correct |
3 |
Correct |
2 ms |
2644 KB |
Output is correct |
4 |
Correct |
2 ms |
2664 KB |
Output is correct |
5 |
Correct |
2 ms |
2644 KB |
Output is correct |
6 |
Correct |
2 ms |
2660 KB |
Output is correct |
7 |
Correct |
1 ms |
2644 KB |
Output is correct |
8 |
Correct |
2 ms |
2644 KB |
Output is correct |
9 |
Correct |
1 ms |
2644 KB |
Output is correct |
10 |
Correct |
2 ms |
2644 KB |
Output is correct |
11 |
Correct |
1 ms |
2668 KB |
Output is correct |
12 |
Correct |
2 ms |
2672 KB |
Output is correct |
13 |
Correct |
1 ms |
2644 KB |
Output is correct |
14 |
Correct |
1 ms |
2644 KB |
Output is correct |
15 |
Correct |
1 ms |
2660 KB |
Output is correct |
16 |
Correct |
1 ms |
2644 KB |
Output is correct |
17 |
Correct |
76 ms |
17868 KB |
Output is correct |
18 |
Correct |
94 ms |
17740 KB |
Output is correct |
19 |
Correct |
74 ms |
18036 KB |
Output is correct |
20 |
Correct |
71 ms |
17840 KB |
Output is correct |
21 |
Correct |
73 ms |
17760 KB |
Output is correct |
22 |
Correct |
71 ms |
18028 KB |
Output is correct |
23 |
Correct |
65 ms |
11540 KB |
Output is correct |
24 |
Correct |
72 ms |
12440 KB |
Output is correct |
25 |
Correct |
79 ms |
12656 KB |
Output is correct |
26 |
Correct |
2 ms |
2644 KB |
Output is correct |
27 |
Correct |
31 ms |
5864 KB |
Output is correct |
28 |
Correct |
73 ms |
12248 KB |
Output is correct |
29 |
Correct |
93 ms |
12376 KB |
Output is correct |
30 |
Correct |
70 ms |
12508 KB |
Output is correct |
31 |
Correct |
73 ms |
12748 KB |
Output is correct |
32 |
Correct |
73 ms |
12292 KB |
Output is correct |
33 |
Correct |
99 ms |
12904 KB |
Output is correct |
34 |
Correct |
1 ms |
2644 KB |
Output is correct |
35 |
Correct |
1 ms |
2668 KB |
Output is correct |
36 |
Correct |
1 ms |
2644 KB |
Output is correct |
37 |
Correct |
2 ms |
2644 KB |
Output is correct |
38 |
Correct |
1 ms |
2644 KB |
Output is correct |
39 |
Correct |
1 ms |
2644 KB |
Output is correct |
40 |
Correct |
1 ms |
2664 KB |
Output is correct |
41 |
Correct |
1 ms |
2644 KB |
Output is correct |
42 |
Correct |
2 ms |
2612 KB |
Output is correct |
43 |
Correct |
1 ms |
2644 KB |
Output is correct |
44 |
Correct |
2 ms |
2644 KB |
Output is correct |
45 |
Correct |
73 ms |
17988 KB |
Output is correct |
46 |
Correct |
72 ms |
17788 KB |
Output is correct |
47 |
Correct |
82 ms |
17988 KB |
Output is correct |
48 |
Correct |
64 ms |
11588 KB |
Output is correct |
49 |
Correct |
71 ms |
12372 KB |
Output is correct |
50 |
Correct |
86 ms |
12676 KB |
Output is correct |
51 |
Correct |
2 ms |
2644 KB |
Output is correct |
52 |
Correct |
26 ms |
5980 KB |
Output is correct |
53 |
Correct |
72 ms |
12140 KB |
Output is correct |
54 |
Correct |
74 ms |
12388 KB |
Output is correct |
55 |
Correct |
74 ms |
12504 KB |
Output is correct |
56 |
Correct |
79 ms |
12836 KB |
Output is correct |
57 |
Correct |
69 ms |
12236 KB |
Output is correct |
58 |
Correct |
72 ms |
12920 KB |
Output is correct |
59 |
Correct |
25 ms |
5800 KB |
Output is correct |
60 |
Correct |
63 ms |
11332 KB |
Output is correct |
61 |
Correct |
98 ms |
12116 KB |
Output is correct |
62 |
Correct |
77 ms |
12360 KB |
Output is correct |
63 |
Correct |
72 ms |
12276 KB |
Output is correct |
64 |
Correct |
72 ms |
12348 KB |
Output is correct |
65 |
Correct |
79 ms |
12876 KB |
Output is correct |
66 |
Correct |
75 ms |
12872 KB |
Output is correct |
67 |
Correct |
65 ms |
12524 KB |
Output is correct |
68 |
Correct |
69 ms |
12612 KB |
Output is correct |
69 |
Correct |
76 ms |
12640 KB |
Output is correct |
70 |
Correct |
67 ms |
12616 KB |
Output is correct |