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Submission #583502

# Submission time Handle Problem Language Result Execution time Memory
583502 2022-06-25T12:44:53 Z WongChun1234 The Xana coup (BOI21_xanadu) C++14
100 / 100
 146 ms 27484 KB 
#include<bits/stdc++.h>
using namespace std;
const int N=100050;
int n,u,v;
long long dp[2][2][N];
bool st[N];
vector<int> adj[N];
void dfs(int nde,int par=-1){
	//flip now? is on?
	bool pt=1;
	long long curr[2][2][2]={{{0,0},{0,0}},{{INT_MAX,INT_MAX},{INT_MAX,INT_MAX}}};
	//chosen%2 flip this
	for (int i:adj[nde]){
		if (i==par) continue;
		dfs(i,nde);
		curr[0][0][pt]=min(curr[0][0][!pt]+dp[0][0][i],curr[1][0][!pt]+dp[1][0][i]);
		curr[0][1][pt]=min(curr[0][1][!pt]+dp[0][1][i],curr[1][1][!pt]+dp[1][1][i]);
		curr[1][0][pt]=min(curr[1][0][!pt]+dp[0][0][i],curr[0][0][!pt]+dp[1][0][i]);
		curr[1][1][pt]=min(curr[1][1][!pt]+dp[0][1][i],curr[0][1][!pt]+dp[1][1][i]);
		//cerr<<nde<<"::"<<curr[0][0][pt]<<" "<<curr[0][1][pt]<<" "<<curr[1][0][pt]<<" "<<curr[1][1][pt]<<"\n";
		pt^=1;
	}
	//no flip
	dp[0][0][nde]=curr[st[nde]][0][!pt];
	dp[0][1][nde]=curr[!st[nde]][0][!pt];
	//flip
	dp[1][0][nde]=curr[!st[nde]][1][!pt]+1;
	dp[1][1][nde]=curr[st[nde]][1][!pt]+1;
	//cout<<nde<<"::"<<st[nde]<<": noflip:"<<dp[0][0][nde]<<" "<<dp[0][1][nde]<<" flip:"<<dp[1][0][nde]<<" "<<dp[1][1][nde]<<"\n";
}
int main(){
	cin>>n;
	for (int i=1;i<n;i++){
		cin>>u>>v;
		adj[u].push_back(v);
		adj[v].push_back(u);
	}
	for (int i=1;i<=n;i++) cin>>st[i];
	dfs(1);
	long long ans=min(dp[0][0][1],dp[1][0][1]);
	if (ans>=1e9) cout<<"impossible\n";
	else cout<<ans<<"\n";
}

Subtask #1
5.0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 2644 KB Output is correct
2 Correct 1 ms 2644 KB Output is correct
3 Correct 1 ms 2644 KB Output is correct
4 Correct 2 ms 2644 KB Output is correct
5 Correct 2 ms 2660 KB Output is correct

Subtask #2
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 2644 KB Output is correct
2 Correct 1 ms 2644 KB Output is correct
3 Correct 1 ms 2644 KB Output is correct
4 Correct 2 ms 2644 KB Output is correct
5 Correct 2 ms 2660 KB Output is correct
6 Correct 3 ms 2656 KB Output is correct
7 Correct 2 ms 2664 KB Output is correct
8 Correct 2 ms 2644 KB Output is correct
9 Correct 2 ms 2644 KB Output is correct
10 Correct 3 ms 2660 KB Output is correct
11 Correct 2 ms 2644 KB Output is correct
12 Correct 2 ms 2644 KB Output is correct
13 Correct 2 ms 2644 KB Output is correct
14 Correct 2 ms 2660 KB Output is correct
15 Correct 3 ms 2644 KB Output is correct
16 Correct 2 ms 2644 KB Output is correct

Subtask #3
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 136 ms 27356 KB Output is correct
2 Correct 120 ms 27136 KB Output is correct
3 Correct 110 ms 27456 KB Output is correct

Subtask #4
40.0 / 40.0

# Verdict Execution time Memory Grader output
1 Correct 134 ms 27396 KB Output is correct
2 Correct 114 ms 27112 KB Output is correct
3 Correct 146 ms 27468 KB Output is correct
4 Correct 100 ms 9428 KB Output is correct
5 Correct 105 ms 10188 KB Output is correct
6 Correct 110 ms 10272 KB Output is correct
7 Correct 2 ms 2644 KB Output is correct
8 Correct 42 ms 5280 KB Output is correct
9 Correct 130 ms 10356 KB Output is correct
10 Correct 107 ms 10444 KB Output is correct
11 Correct 104 ms 11524 KB Output is correct
12 Correct 113 ms 11884 KB Output is correct
13 Correct 102 ms 9804 KB Output is correct
14 Correct 104 ms 10316 KB Output is correct

Subtask #5
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 2644 KB Output is correct
2 Correct 1 ms 2644 KB Output is correct
3 Correct 1 ms 2644 KB Output is correct
4 Correct 2 ms 2644 KB Output is correct
5 Correct 2 ms 2660 KB Output is correct
6 Correct 3 ms 2656 KB Output is correct
7 Correct 2 ms 2664 KB Output is correct
8 Correct 2 ms 2644 KB Output is correct
9 Correct 2 ms 2644 KB Output is correct
10 Correct 3 ms 2660 KB Output is correct
11 Correct 2 ms 2644 KB Output is correct
12 Correct 2 ms 2644 KB Output is correct
13 Correct 2 ms 2644 KB Output is correct
14 Correct 2 ms 2660 KB Output is correct
15 Correct 3 ms 2644 KB Output is correct
16 Correct 2 ms 2644 KB Output is correct
17 Correct 136 ms 27356 KB Output is correct
18 Correct 120 ms 27136 KB Output is correct
19 Correct 110 ms 27456 KB Output is correct
20 Correct 134 ms 27396 KB Output is correct
21 Correct 114 ms 27112 KB Output is correct
22 Correct 146 ms 27468 KB Output is correct
23 Correct 100 ms 9428 KB Output is correct
24 Correct 105 ms 10188 KB Output is correct
25 Correct 110 ms 10272 KB Output is correct
26 Correct 2 ms 2644 KB Output is correct
27 Correct 42 ms 5280 KB Output is correct
28 Correct 130 ms 10356 KB Output is correct
29 Correct 107 ms 10444 KB Output is correct
30 Correct 104 ms 11524 KB Output is correct
31 Correct 113 ms 11884 KB Output is correct
32 Correct 102 ms 9804 KB Output is correct
33 Correct 104 ms 10316 KB Output is correct
34 Correct 3 ms 2644 KB Output is correct
35 Correct 3 ms 2644 KB Output is correct
36 Correct 2 ms 2644 KB Output is correct
37 Correct 2 ms 2668 KB Output is correct
38 Correct 2 ms 2644 KB Output is correct
39 Correct 2 ms 2644 KB Output is correct
40 Correct 2 ms 2644 KB Output is correct
41 Correct 2 ms 2616 KB Output is correct
42 Correct 2 ms 2644 KB Output is correct
43 Correct 2 ms 2644 KB Output is correct
44 Correct 2 ms 2644 KB Output is correct
45 Correct 122 ms 27448 KB Output is correct
46 Correct 103 ms 27100 KB Output is correct
47 Correct 129 ms 27484 KB Output is correct
48 Correct 124 ms 9456 KB Output is correct
49 Correct 129 ms 10124 KB Output is correct
50 Correct 99 ms 10384 KB Output is correct
51 Correct 2 ms 2644 KB Output is correct
52 Correct 32 ms 5288 KB Output is correct
53 Correct 95 ms 10284 KB Output is correct
54 Correct 109 ms 10512 KB Output is correct
55 Correct 124 ms 11552 KB Output is correct
56 Correct 124 ms 11960 KB Output is correct
57 Correct 89 ms 9804 KB Output is correct
58 Correct 104 ms 10256 KB Output is correct
59 Correct 35 ms 5236 KB Output is correct
60 Correct 92 ms 9580 KB Output is correct
61 Correct 124 ms 10376 KB Output is correct
62 Correct 117 ms 10452 KB Output is correct
63 Correct 98 ms 10444 KB Output is correct
64 Correct 105 ms 10504 KB Output is correct
65 Correct 104 ms 10828 KB Output is correct
66 Correct 95 ms 10860 KB Output is correct
67 Correct 85 ms 10724 KB Output is correct
68 Correct 85 ms 10712 KB Output is correct
69 Correct 100 ms 10692 KB Output is correct
70 Correct 97 ms 10740 KB Output is correct