oj.uz

답안 #433297

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
433297 2021-06-19T13:26:09 Z couplefire The Xana coup (BOI21_xanadu) C++17
100 / 100
 112 ms 23116 KB 
#include <bits/stdc++.h>
using namespace std;

const int N = 100005;
const int INF = 0x3f3f3f3f;

int ckmin(int& x, int y){return x>y?x=y:x;}

int n;
vector<int> adj[N];
int arr[N];
int dp[N][2][2]; // vertex, value of the current node, whether this node is chosen

void dfs(int v, int p){
    int tmp[2][2][2];
    memset(tmp, INF, sizeof tmp);
    tmp[0][0][0] = tmp[0][1][0] = 0;
    for(auto u : adj[v]){
        if(u == p) continue;
        dfs(u, v);
        memset(tmp[1], INF, sizeof tmp[1]);
        for(int a = 0; a<2; a++) // dp & tmp
            for(int b = 0; b<2; b++) // dp
                for(int c = 0; c<2; c++) // tmp
                    ckmin(tmp[1][a][b^c], dp[u][a][b]+tmp[0][a][c]);
        swap(tmp[0], tmp[1]);
    }
    dp[v][0][0] = tmp[0][0][arr[v]];
    dp[v][0][1] = tmp[0][1][1^arr[v]]+1;
    dp[v][1][0] = tmp[0][0][1^arr[v]];
    dp[v][1][1] = tmp[0][1][arr[v]]+1;
}

int main(){
    // freopen("a.in", "r", stdin);
    ios_base::sync_with_stdio(false);
    cin.tie(0);
    cin >> n;
    for(int i = 0; i<n-1; i++){
        int a, b; cin >> a >> b; --a; --b;
        adj[a].push_back(b);
        adj[b].push_back(a);
    }
    for(int i = 0; i<n; i++)
        cin >> arr[i];
    memset(dp, INF, sizeof dp);
    dfs(0, -1);
    int ans = min(dp[0][0][0], dp[0][0][1]);
    if(ans == INF) cout << "impossible" << '\n';
    else cout << ans << '\n';
}

Subtask #1
5.0 / 5.0

# 결과 실행 시간 메모리 Grader output
1 Correct 3 ms 4172 KB Output is correct
2 Correct 3 ms 4172 KB Output is correct
3 Correct 3 ms 4208 KB Output is correct
4 Correct 3 ms 4172 KB Output is correct
5 Correct 3 ms 4204 KB Output is correct

Subtask #2
15.0 / 15.0

# 결과 실행 시간 메모리 Grader output
1 Correct 3 ms 4172 KB Output is correct
2 Correct 3 ms 4172 KB Output is correct
3 Correct 3 ms 4208 KB Output is correct
4 Correct 3 ms 4172 KB Output is correct
5 Correct 3 ms 4204 KB Output is correct
6 Correct 3 ms 4172 KB Output is correct
7 Correct 3 ms 4172 KB Output is correct
8 Correct 3 ms 4172 KB Output is correct
9 Correct 3 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 4208 KB Output is correct
13 Correct 3 ms 4180 KB Output is correct
14 Correct 3 ms 4172 KB Output is correct
15 Correct 3 ms 4172 KB Output is correct
16 Correct 3 ms 4172 KB Output is correct

Subtask #3
10.0 / 10.0

# 결과 실행 시간 메모리 Grader output
1 Correct 85 ms 22980 KB Output is correct
2 Correct 71 ms 22848 KB Output is correct
3 Correct 74 ms 23116 KB Output is correct

Subtask #4
40.0 / 40.0

# 결과 실행 시간 메모리 Grader output
1 Correct 65 ms 22964 KB Output is correct
2 Correct 71 ms 22844 KB Output is correct
3 Correct 78 ms 23108 KB Output is correct
4 Correct 98 ms 8536 KB Output is correct
5 Correct 112 ms 8984 KB Output is correct
6 Correct 78 ms 9048 KB Output is correct
7 Correct 3 ms 4172 KB Output is correct
8 Correct 20 ms 5928 KB Output is correct
9 Correct 72 ms 9140 KB Output is correct
10 Correct 95 ms 9156 KB Output is correct
11 Correct 87 ms 10120 KB Output is correct
12 Correct 84 ms 10292 KB Output is correct
13 Correct 65 ms 8708 KB Output is correct
14 Correct 81 ms 9076 KB Output is correct

Subtask #5
30.0 / 30.0

# 결과 실행 시간 메모리 Grader output
1 Correct 3 ms 4172 KB Output is correct
2 Correct 3 ms 4172 KB Output is correct
3 Correct 3 ms 4208 KB Output is correct
4 Correct 3 ms 4172 KB Output is correct
5 Correct 3 ms 4204 KB Output is correct
6 Correct 3 ms 4172 KB Output is correct
7 Correct 3 ms 4172 KB Output is correct
8 Correct 3 ms 4172 KB Output is correct
9 Correct 3 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 4208 KB Output is correct
13 Correct 3 ms 4180 KB Output is correct
14 Correct 3 ms 4172 KB Output is correct
15 Correct 3 ms 4172 KB Output is correct
16 Correct 3 ms 4172 KB Output is correct
17 Correct 85 ms 22980 KB Output is correct
18 Correct 71 ms 22848 KB Output is correct
19 Correct 74 ms 23116 KB Output is correct
20 Correct 65 ms 22964 KB Output is correct
21 Correct 71 ms 22844 KB Output is correct
22 Correct 78 ms 23108 KB Output is correct
23 Correct 98 ms 8536 KB Output is correct
24 Correct 112 ms 8984 KB Output is correct
25 Correct 78 ms 9048 KB Output is correct
26 Correct 3 ms 4172 KB Output is correct
27 Correct 20 ms 5928 KB Output is correct
28 Correct 72 ms 9140 KB Output is correct
29 Correct 95 ms 9156 KB Output is correct
30 Correct 87 ms 10120 KB Output is correct
31 Correct 84 ms 10292 KB Output is correct
32 Correct 65 ms 8708 KB Output is correct
33 Correct 81 ms 9076 KB Output is correct
34 Correct 3 ms 4208 KB Output is correct
35 Correct 3 ms 4172 KB Output is correct
36 Correct 3 ms 4172 KB Output is correct
37 Correct 3 ms 4208 KB Output is correct
38 Correct 3 ms 4172 KB Output is correct
39 Correct 3 ms 4204 KB Output is correct
40 Correct 3 ms 4212 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 4172 KB Output is correct
44 Correct 3 ms 4172 KB Output is correct
45 Correct 72 ms 23060 KB Output is correct
46 Correct 86 ms 22848 KB Output is correct
47 Correct 62 ms 23116 KB Output is correct
48 Correct 63 ms 8552 KB Output is correct
49 Correct 77 ms 8928 KB Output is correct
50 Correct 73 ms 9016 KB Output is correct
51 Correct 3 ms 4172 KB Output is correct
52 Correct 23 ms 5868 KB Output is correct
53 Correct 85 ms 9140 KB Output is correct
54 Correct 67 ms 9152 KB Output is correct
55 Correct 78 ms 10156 KB Output is correct
56 Correct 83 ms 10312 KB Output is correct
57 Correct 90 ms 8772 KB Output is correct
58 Correct 69 ms 9024 KB Output is correct
59 Correct 20 ms 5852 KB Output is correct
60 Correct 62 ms 8644 KB Output is correct
61 Correct 82 ms 9044 KB Output is correct
62 Correct 89 ms 9236 KB Output is correct
63 Correct 81 ms 9156 KB Output is correct
64 Correct 64 ms 9176 KB Output is correct
65 Correct 67 ms 9568 KB Output is correct
66 Correct 62 ms 9588 KB Output is correct
67 Correct 66 ms 9428 KB Output is correct
68 Correct 63 ms 9404 KB Output is correct
69 Correct 51 ms 9404 KB Output is correct
70 Correct 54 ms 9444 KB Output is correct