oj.uz

Submission #401013

# Submission time Handle Problem Language Result Execution time Memory
401013 2021-05-09T06:51:31 Z errorgorn The Xana coup (BOI21_xanadu) C++17
100 / 100
 113 ms 20036 KB 
#include <bits/stdc++.h>
using namespace std;

#define ll long long
#define ii pair<int,int>
#define fi first
#define se second
#define endl '\n'

#define puf push_front
#define pof pop_front
#define pub push_back
#define pob pop_back

#define rep(x,s,e) for (auto x=s-(s>e);x!=e-(s>e);(s<e?x++:x--))
#define all(x) (x).begin(),(x).end()
#define sz(x) (int) (x).size()

const int INF=1e9;

int n;
int arr[100005];
vector<int> al[100005];

int memo[100005][2][2];
int dfs(int i,int p,int on,int toggle){
	if (memo[i][on][toggle]!=-1) return memo[i][on][toggle];
	
	//if toggle=false, then our children must be on=false
	//else children must be on=true
	
	int val[2]={INF,INF};
	val[arr[i]]=0;
	
	for (auto &it:al[i]){
		if (it==p) continue;
		
		int tf=dfs(it,i,toggle,false);
		int tt=dfs(it,i,toggle,true);
		
		int temp[2]={min({val[0]+tf,val[1]+tt,INF}),
					 min({val[0]+tt,val[1]+tf,INF})};
		swap(val,temp);
	}
	
	//cout<<i<<" "<<on<<" "<<toggle<<" "<<val[on]+toggle<<endl;
	return memo[i][on][toggle]=val[on^toggle]+toggle;
}

int main(){
	cin.tie(0);
	cout.tie(0);
	cin.sync_with_stdio(false);
	
	cin>>n;
	
	int a,b;
	rep(x,1,n){
		cin>>a>>b;
		al[a].pub(b);
		al[b].pub(a);
	}
	
	rep(x,1,n+1) cin>>arr[x];
	
	memset(memo,-1,sizeof(memo));
	
	int ans=min(dfs(1,-1,0,0),dfs(1,-1,0,1));
	
	//cout<<dfs(1,-1,0,0)<<endl;
	//cout<<dfs(1,-1,0,1)<<endl;
	
	if (ans<1e9) cout<<ans<<endl;
	else cout<<"impossible"<<endl;
}

Subtask #1
5.0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 4172 KB Output is correct
2 Correct 3 ms 4172 KB Output is correct
3 Correct 3 ms 4172 KB Output is correct
4 Correct 3 ms 4212 KB Output is correct
5 Correct 3 ms 4172 KB Output is correct

Subtask #2
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 4172 KB Output is correct
2 Correct 3 ms 4172 KB Output is correct
3 Correct 3 ms 4172 KB Output is correct
4 Correct 3 ms 4212 KB Output is correct
5 Correct 3 ms 4172 KB Output is correct
6 Correct 3 ms 4172 KB Output is correct
7 Correct 3 ms 4172 KB Output is correct
8 Correct 4 ms 4172 KB Output is correct
9 Correct 4 ms 4172 KB Output is correct
10 Correct 3 ms 4172 KB Output is correct
11 Correct 3 ms 4172 KB Output is correct
12 Correct 3 ms 4220 KB Output is correct
13 Correct 3 ms 4172 KB Output is correct
14 Correct 4 ms 4172 KB Output is correct
15 Correct 4 ms 4160 KB Output is correct
16 Correct 3 ms 4172 KB Output is correct

Subtask #3
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 88 ms 19956 KB Output is correct
2 Correct 91 ms 19704 KB Output is correct
3 Correct 77 ms 20036 KB Output is correct

Subtask #4
40.0 / 40.0

# Verdict Execution time Memory Grader output
1 Correct 74 ms 19956 KB Output is correct
2 Correct 76 ms 19856 KB Output is correct
3 Correct 67 ms 20012 KB Output is correct
4 Correct 79 ms 8548 KB Output is correct
5 Correct 67 ms 8908 KB Output is correct
6 Correct 113 ms 9088 KB Output is correct
7 Correct 4 ms 4172 KB Output is correct
8 Correct 25 ms 5844 KB Output is correct
9 Correct 74 ms 9092 KB Output is correct
10 Correct 73 ms 9196 KB Output is correct
11 Correct 69 ms 9884 KB Output is correct
12 Correct 73 ms 10004 KB Output is correct
13 Correct 59 ms 8780 KB Output is correct
14 Correct 64 ms 8980 KB Output is correct

Subtask #5
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 4172 KB Output is correct
2 Correct 3 ms 4172 KB Output is correct
3 Correct 3 ms 4172 KB Output is correct
4 Correct 3 ms 4212 KB Output is correct
5 Correct 3 ms 4172 KB Output is correct
6 Correct 3 ms 4172 KB Output is correct
7 Correct 3 ms 4172 KB Output is correct
8 Correct 4 ms 4172 KB Output is correct
9 Correct 4 ms 4172 KB Output is correct
10 Correct 3 ms 4172 KB Output is correct
11 Correct 3 ms 4172 KB Output is correct
12 Correct 3 ms 4220 KB Output is correct
13 Correct 3 ms 4172 KB Output is correct
14 Correct 4 ms 4172 KB Output is correct
15 Correct 4 ms 4160 KB Output is correct
16 Correct 3 ms 4172 KB Output is correct
17 Correct 88 ms 19956 KB Output is correct
18 Correct 91 ms 19704 KB Output is correct
19 Correct 77 ms 20036 KB Output is correct
20 Correct 74 ms 19956 KB Output is correct
21 Correct 76 ms 19856 KB Output is correct
22 Correct 67 ms 20012 KB Output is correct
23 Correct 79 ms 8548 KB Output is correct
24 Correct 67 ms 8908 KB Output is correct
25 Correct 113 ms 9088 KB Output is correct
26 Correct 4 ms 4172 KB Output is correct
27 Correct 25 ms 5844 KB Output is correct
28 Correct 74 ms 9092 KB Output is correct
29 Correct 73 ms 9196 KB Output is correct
30 Correct 69 ms 9884 KB Output is correct
31 Correct 73 ms 10004 KB Output is correct
32 Correct 59 ms 8780 KB Output is correct
33 Correct 64 ms 8980 KB Output is correct
34 Correct 5 ms 4172 KB Output is correct
35 Correct 3 ms 4220 KB Output is correct
36 Correct 3 ms 4172 KB Output is correct
37 Correct 3 ms 4172 KB Output is correct
38 Correct 3 ms 4172 KB Output is correct
39 Correct 3 ms 4172 KB Output is correct
40 Correct 5 ms 4176 KB Output is correct
41 Correct 3 ms 4172 KB Output is correct
42 Correct 3 ms 4172 KB Output is correct
43 Correct 3 ms 4216 KB Output is correct
44 Correct 6 ms 4172 KB Output is correct
45 Correct 79 ms 19936 KB Output is correct
46 Correct 78 ms 19680 KB Output is correct
47 Correct 69 ms 19936 KB Output is correct
48 Correct 62 ms 8516 KB Output is correct
49 Correct 68 ms 8884 KB Output is correct
50 Correct 67 ms 9028 KB Output is correct
51 Correct 3 ms 4172 KB Output is correct
52 Correct 30 ms 5892 KB Output is correct
53 Correct 75 ms 9044 KB Output is correct
54 Correct 71 ms 9096 KB Output is correct
55 Correct 75 ms 9824 KB Output is correct
56 Correct 81 ms 10080 KB Output is correct
57 Correct 64 ms 8772 KB Output is correct
58 Correct 67 ms 9084 KB Output is correct
59 Correct 21 ms 5788 KB Output is correct
60 Correct 91 ms 8572 KB Output is correct
61 Correct 64 ms 9084 KB Output is correct
62 Correct 80 ms 9128 KB Output is correct
63 Correct 107 ms 9212 KB Output is correct
64 Correct 72 ms 9116 KB Output is correct
65 Correct 64 ms 9520 KB Output is correct
66 Correct 62 ms 9540 KB Output is correct
67 Correct 54 ms 9476 KB Output is correct
68 Correct 73 ms 9496 KB Output is correct
69 Correct 55 ms 9404 KB Output is correct
70 Correct 57 ms 9404 KB Output is correct