oj.uz

Submission #574275

# Submission time Handle Problem Language Result Execution time Memory
574275 2022-06-08T09:30:14 Z amunduzbaev The Xana coup (BOI21_xanadu) C++17
100 / 100
 86 ms 29796 KB 
#include "bits/stdc++.h"
using namespace std;

#define ar array
#define int long long
const int N = 1e5 + 5;
vector<int> edges[N];
int a[N], dp[2][2][N];

void dfs(int u, int p = -1){
	vector<ar<int, 2>> t[2];
	dp[0][0][u] = dp[0][1][u] = dp[1][0][u] = dp[1][1][u] = N;
	for(auto x : edges[u]){
		if(x == p) continue;
		dfs(x, u);
		t[0].push_back({dp[0][0][x], dp[0][1][x]});
		t[1].push_back({dp[1][0][x], dp[1][1][x]});
	}
	int m = t[0].size();
	if(!m){
		dp[a[u]][0][u] = 0, dp[a[u] ^ 1][1][u] = 1;
		return;
	}
	
	for(int k=0;k<2;k++){
		int res = 0;
		for(auto x : t[k]) res += x[0];
		sort(t[k].begin(), t[k].end(), [&](auto& a, auto& b){
			return (a[1] - a[0] < b[1] - b[0]);
		});
		for(int x=0;x<=m;x++){
			int is = a[u] ^ (x & 1) ^ k;
			dp[is][k][u] = min(dp[is][k][u], res + k);
			if(x < m){
				res = res - t[k][x][0] + t[k][x][1];
			}
		}
	}
}

signed main(){
	ios::sync_with_stdio(0); cin.tie(0);
	
	int n; cin>>n;
	for(int i=1;i<n;i++){
		int a, b; cin>>a>>b;
		edges[a].push_back(b);
		edges[b].push_back(a);
	}
	
	for(int i=1;i<=n;i++){
		cin>>a[i];
	}
	
	dfs(1);
	int res = min(dp[0][0][1], dp[0][1][1]);
	if(res >= N){
		cout<<"impossible\n";
	} else {
		cout<<res<<"\n";
	}
}

Subtask #1
5.0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 2644 KB Output is correct
2 Correct 2 ms 2680 KB Output is correct
3 Correct 2 ms 2644 KB Output is correct
4 Correct 2 ms 2644 KB Output is correct
5 Correct 1 ms 2644 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 2 ms 2680 KB Output is correct
3 Correct 2 ms 2644 KB Output is correct
4 Correct 2 ms 2644 KB Output is correct
5 Correct 1 ms 2644 KB Output is correct
6 Correct 2 ms 2676 KB Output is correct
7 Correct 2 ms 2644 KB Output is correct
8 Correct 2 ms 2684 KB Output is correct
9 Correct 2 ms 2644 KB Output is correct
10 Correct 1 ms 2644 KB Output is correct
11 Correct 1 ms 2644 KB Output is correct
12 Correct 2 ms 2644 KB Output is correct
13 Correct 1 ms 2644 KB Output is correct
14 Correct 1 ms 2644 KB Output is correct
15 Correct 2 ms 2644 KB Output is correct
16 Correct 2 ms 2680 KB Output is correct

Subtask #3
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 64 ms 28276 KB Output is correct
2 Correct 80 ms 28180 KB Output is correct
3 Correct 66 ms 28604 KB Output is correct

Subtask #4
40.0 / 40.0

# Verdict Execution time Memory Grader output
1 Correct 73 ms 28236 KB Output is correct
2 Correct 71 ms 28296 KB Output is correct
3 Correct 70 ms 28556 KB Output is correct
4 Correct 59 ms 9776 KB Output is correct
5 Correct 68 ms 11736 KB Output is correct
6 Correct 79 ms 11932 KB Output is correct
7 Correct 2 ms 2644 KB Output is correct
8 Correct 22 ms 5716 KB Output is correct
9 Correct 66 ms 11636 KB Output is correct
10 Correct 66 ms 11772 KB Output is correct
11 Correct 86 ms 13004 KB Output is correct
12 Correct 68 ms 13328 KB Output is correct
13 Correct 69 ms 11604 KB Output is correct
14 Correct 76 ms 12232 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 2 ms 2680 KB Output is correct
3 Correct 2 ms 2644 KB Output is correct
4 Correct 2 ms 2644 KB Output is correct
5 Correct 1 ms 2644 KB Output is correct
6 Correct 2 ms 2676 KB Output is correct
7 Correct 2 ms 2644 KB Output is correct
8 Correct 2 ms 2684 KB Output is correct
9 Correct 2 ms 2644 KB Output is correct
10 Correct 1 ms 2644 KB Output is correct
11 Correct 1 ms 2644 KB Output is correct
12 Correct 2 ms 2644 KB Output is correct
13 Correct 1 ms 2644 KB Output is correct
14 Correct 1 ms 2644 KB Output is correct
15 Correct 2 ms 2644 KB Output is correct
16 Correct 2 ms 2680 KB Output is correct
17 Correct 64 ms 28276 KB Output is correct
18 Correct 80 ms 28180 KB Output is correct
19 Correct 66 ms 28604 KB Output is correct
20 Correct 73 ms 28236 KB Output is correct
21 Correct 71 ms 28296 KB Output is correct
22 Correct 70 ms 28556 KB Output is correct
23 Correct 59 ms 9776 KB Output is correct
24 Correct 68 ms 11736 KB Output is correct
25 Correct 79 ms 11932 KB Output is correct
26 Correct 2 ms 2644 KB Output is correct
27 Correct 22 ms 5716 KB Output is correct
28 Correct 66 ms 11636 KB Output is correct
29 Correct 66 ms 11772 KB Output is correct
30 Correct 86 ms 13004 KB Output is correct
31 Correct 68 ms 13328 KB Output is correct
32 Correct 69 ms 11604 KB Output is correct
33 Correct 76 ms 12232 KB Output is correct
34 Correct 2 ms 2680 KB Output is correct
35 Correct 2 ms 2684 KB Output is correct
36 Correct 2 ms 2680 KB Output is correct
37 Correct 2 ms 2644 KB Output is correct
38 Correct 2 ms 2684 KB Output is correct
39 Correct 2 ms 2644 KB Output is correct
40 Correct 2 ms 2676 KB Output is correct
41 Correct 2 ms 2644 KB Output is correct
42 Correct 3 ms 2644 KB Output is correct
43 Correct 2 ms 2644 KB Output is correct
44 Correct 2 ms 2684 KB Output is correct
45 Correct 67 ms 29584 KB Output is correct
46 Correct 73 ms 29376 KB Output is correct
47 Correct 70 ms 29796 KB Output is correct
48 Correct 72 ms 10960 KB Output is correct
49 Correct 80 ms 11688 KB Output is correct
50 Correct 81 ms 11936 KB Output is correct
51 Correct 2 ms 2676 KB Output is correct
52 Correct 18 ms 5772 KB Output is correct
53 Correct 76 ms 11620 KB Output is correct
54 Correct 73 ms 11784 KB Output is correct
55 Correct 79 ms 12928 KB Output is correct
56 Correct 80 ms 13516 KB Output is correct
57 Correct 82 ms 11640 KB Output is correct
58 Correct 77 ms 12212 KB Output is correct
59 Correct 21 ms 5784 KB Output is correct
60 Correct 71 ms 10764 KB Output is correct
61 Correct 65 ms 11472 KB Output is correct
62 Correct 66 ms 11740 KB Output is correct
63 Correct 68 ms 11744 KB Output is correct
64 Correct 69 ms 11708 KB Output is correct
65 Correct 61 ms 12244 KB Output is correct
66 Correct 62 ms 12072 KB Output is correct
67 Correct 56 ms 15060 KB Output is correct
68 Correct 67 ms 15136 KB Output is correct
69 Correct 46 ms 15080 KB Output is correct
70 Correct 46 ms 15120 KB Output is correct