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Submission #876598

# Submission time Handle Problem Language Result Execution time Memory
876598 2023-11-22T04:06:24 Z floralfield The Xana coup (BOI21_xanadu) C++17
100 / 100
 82 ms 30748 KB 
#include <bits/stdc++.h>
#define int long long
#define fi first
#define se second
#define keish                       \
      ios_base::sync_with_stdio(0); \
      cin.tie(0); cout.tie(0)

using namespace std;

signed main(){
      keish;

      int n;
      cin >> n;

      vector<vector<int>> e(n);
      for(int i = 1; i < n; i++){
            int u, v;
            cin >> u >> v; u--, v--;
            
            e[u].push_back(v);
            e[v].push_back(u);
      }

      vector<int> a(n);
      for(int i = 0; i < n; i++) cin >> a[i];

      vector<bool> vis(n);
      vector dp(n, vector(2, vector<int>(2, n + 5)));

      function<void(int)> dfs = [&](int u){
            vis[u] = 1;

            if(!a[u]){
                  dp[u][0][0] = 0;
                  dp[u][1][1] = 1;
            }else{
                  dp[u][0][1] = 0;
                  dp[u][1][0] = 1;
            }

            for(auto v : e[u]){
                  if(!vis[v]){
                        dfs(v);

                        int x = dp[u][0][0];
                        int y = dp[u][0][1];
                        dp[u][0][0] = min(dp[v][0][0] + x, dp[v][1][0] + y);
                        dp[u][0][1] = min(dp[v][0][0] + y, dp[v][1][0] + x);

                        x = dp[u][1][0];
                        y = dp[u][1][1];
                        dp[u][1][0] = min(dp[v][0][1] + x, dp[v][1][1] + y);
                        dp[u][1][1] = min(dp[v][0][1] + y, dp[v][1][1] + x);
                  }
            }
      };

      dfs(0);

      if(min(dp[0][0][0], dp[0][1][0]) > n){
            cout << "impossible\n";
      }else{
            cout << min(dp[0][0][0], dp[0][1][0]) << '\n';
      }
}

Subtask #1
5.0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 348 KB Output is correct
2 Correct 0 ms 348 KB Output is correct
3 Correct 1 ms 344 KB Output is correct
4 Correct 0 ms 348 KB Output is correct
5 Correct 0 ms 348 KB Output is correct

Subtask #2
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 348 KB Output is correct
2 Correct 0 ms 348 KB Output is correct
3 Correct 1 ms 344 KB Output is correct
4 Correct 0 ms 348 KB Output is correct
5 Correct 0 ms 348 KB Output is correct
6 Correct 1 ms 348 KB Output is correct
7 Correct 0 ms 348 KB Output is correct
8 Correct 0 ms 348 KB Output is correct
9 Correct 0 ms 348 KB Output is correct
10 Correct 0 ms 348 KB Output is correct
11 Correct 0 ms 344 KB Output is correct
12 Correct 0 ms 348 KB Output is correct
13 Correct 0 ms 348 KB Output is correct
14 Correct 0 ms 348 KB Output is correct
15 Correct 1 ms 344 KB Output is correct
16 Correct 1 ms 344 KB Output is correct

Subtask #3
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 53 ms 30540 KB Output is correct
2 Correct 55 ms 30196 KB Output is correct
3 Correct 58 ms 30748 KB Output is correct

Subtask #4
40.0 / 40.0

# Verdict Execution time Memory Grader output
1 Correct 56 ms 30532 KB Output is correct
2 Correct 53 ms 30204 KB Output is correct
3 Correct 52 ms 30664 KB Output is correct
4 Correct 60 ms 21072 KB Output is correct
5 Correct 74 ms 22988 KB Output is correct
6 Correct 62 ms 23384 KB Output is correct
7 Correct 1 ms 344 KB Output is correct
8 Correct 16 ms 8024 KB Output is correct
9 Correct 73 ms 22864 KB Output is correct
10 Correct 68 ms 23264 KB Output is correct
11 Correct 64 ms 23100 KB Output is correct
12 Correct 82 ms 23804 KB Output is correct
13 Correct 72 ms 22220 KB Output is correct
14 Correct 62 ms 23632 KB Output is correct

Subtask #5
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 348 KB Output is correct
2 Correct 0 ms 348 KB Output is correct
3 Correct 1 ms 344 KB Output is correct
4 Correct 0 ms 348 KB Output is correct
5 Correct 0 ms 348 KB Output is correct
6 Correct 1 ms 348 KB Output is correct
7 Correct 0 ms 348 KB Output is correct
8 Correct 0 ms 348 KB Output is correct
9 Correct 0 ms 348 KB Output is correct
10 Correct 0 ms 348 KB Output is correct
11 Correct 0 ms 344 KB Output is correct
12 Correct 0 ms 348 KB Output is correct
13 Correct 0 ms 348 KB Output is correct
14 Correct 0 ms 348 KB Output is correct
15 Correct 1 ms 344 KB Output is correct
16 Correct 1 ms 344 KB Output is correct
17 Correct 53 ms 30540 KB Output is correct
18 Correct 55 ms 30196 KB Output is correct
19 Correct 58 ms 30748 KB Output is correct
20 Correct 56 ms 30532 KB Output is correct
21 Correct 53 ms 30204 KB Output is correct
22 Correct 52 ms 30664 KB Output is correct
23 Correct 60 ms 21072 KB Output is correct
24 Correct 74 ms 22988 KB Output is correct
25 Correct 62 ms 23384 KB Output is correct
26 Correct 1 ms 344 KB Output is correct
27 Correct 16 ms 8024 KB Output is correct
28 Correct 73 ms 22864 KB Output is correct
29 Correct 68 ms 23264 KB Output is correct
30 Correct 64 ms 23100 KB Output is correct
31 Correct 82 ms 23804 KB Output is correct
32 Correct 72 ms 22220 KB Output is correct
33 Correct 62 ms 23632 KB Output is correct
34 Correct 0 ms 348 KB Output is correct
35 Correct 0 ms 348 KB Output is correct
36 Correct 0 ms 348 KB Output is correct
37 Correct 1 ms 556 KB Output is correct
38 Correct 1 ms 344 KB Output is correct
39 Correct 0 ms 348 KB Output is correct
40 Correct 0 ms 452 KB Output is correct
41 Correct 1 ms 348 KB Output is correct
42 Correct 0 ms 348 KB Output is correct
43 Correct 0 ms 348 KB Output is correct
44 Correct 0 ms 348 KB Output is correct
45 Correct 53 ms 30548 KB Output is correct
46 Correct 51 ms 30160 KB Output is correct
47 Correct 55 ms 30620 KB Output is correct
48 Correct 55 ms 20936 KB Output is correct
49 Correct 63 ms 22868 KB Output is correct
50 Correct 76 ms 23340 KB Output is correct
51 Correct 1 ms 348 KB Output is correct
52 Correct 16 ms 7984 KB Output is correct
53 Correct 74 ms 23040 KB Output is correct
54 Correct 69 ms 23380 KB Output is correct
55 Correct 71 ms 23376 KB Output is correct
56 Correct 75 ms 23892 KB Output is correct
57 Correct 76 ms 22308 KB Output is correct
58 Correct 66 ms 23632 KB Output is correct
59 Correct 18 ms 8024 KB Output is correct
60 Correct 52 ms 20816 KB Output is correct
61 Correct 73 ms 22988 KB Output is correct
62 Correct 63 ms 23344 KB Output is correct
63 Correct 62 ms 23380 KB Output is correct
64 Correct 68 ms 23380 KB Output is correct
65 Correct 59 ms 24008 KB Output is correct
66 Correct 80 ms 23824 KB Output is correct
67 Correct 64 ms 23728 KB Output is correct
68 Correct 52 ms 23752 KB Output is correct
69 Correct 54 ms 23752 KB Output is correct
70 Correct 57 ms 23492 KB Output is correct