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Submission #678365

# Submission time Handle Problem Language Result Execution time Memory
678365 2023-01-05T16:12:25 Z Vahe The Xana coup (BOI21_xanadu) C++17
100 / 100
 180 ms 27648 KB 
#include <iostream>
#include <vector>
#include <set>
#include <queue>
#include <deque>
#include <map>
#include <stack>
#include <algorithm>
#include <cmath>
#include <iomanip>
#include <climits>
using namespace std;
using ll = long long;
int n;
vector<int> clr;
vector<vector<int>> gp;
vector<vector<vector<int>>> dp;

void DPcreator(int u, int p, int nerk)
{
    multiset<pair<int, int>> st, zibil;

    bool impossible = 0;
    int MinChange = 2e9;
    for (int& v : gp[u])
    {
        if (v == p) continue;
        if (dp[v][0][nerk] < 2e9 && dp[v][1][nerk] < 2e9)
        {
            st.insert({ min(dp[v][0][nerk], dp[v][1][nerk]), (dp[v][0][nerk] < dp[v][1][nerk] ? 0 : 1) });
            MinChange = min(MinChange, abs(dp[v][0][nerk] - dp[v][1][nerk]));
        }
        else if (dp[v][0][nerk] < 2e9)
            st.insert({ dp[v][0][nerk], 0 });
        else if (dp[v][1][nerk] < 2e9)
            st.insert({ dp[v][1][nerk], 1 });
        else impossible = 1;
    }

    int sum = 0, cnt = clr[u] + nerk;
    for (pair<int, int> i : st)
    {
        cnt += i.second;
        sum += i.first;
    }

    int NotChanged = sum + nerk;

    sum += MinChange;

    int Changed = sum + nerk;
    //
    if (impossible) NotChanged = Changed = 2e9;
    //
    if (cnt & 1) dp[u][nerk][0] = Changed, dp[u][nerk][1] = NotChanged;
    else         dp[u][nerk][0] = NotChanged, dp[u][nerk][1] = Changed;
}

void dfs(int u, int p)
{
    if (gp[u].size() == 1 && u != 0)
    {
        if (clr[u])
        {
            dp[u][0][0] = 2e9;
            dp[u][0][1] = 0;
            dp[u][1][0] = 1;
            dp[u][1][1] = 2e9;
        }
        else
        {
            dp[u][0][0] = 0;
            dp[u][0][1] = 2e9;
            dp[u][1][0] = 2e9;
            dp[u][1][1] = 1;
        }
        return;
    }

    for (int& v : gp[u])
    {
        if (v == p) continue;
        if (dp[v][0][0] == -1) dfs(v, u);
    }

    DPcreator(u, p, 0);
    DPcreator(u, p, 1);
}

int main() {
    int n; cin >> n;
    gp = vector<vector<int>>(n);
    dp = vector<vector<vector<int>>>(n, { {-1, -1}, {-1, -1} });

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

    dfs(0, -1);

    int ans = min(dp[0][0][0], dp[0][1][0]);
    if (ans >= 2e9) cout << "impossible\n";
    else cout << ans << endl;

    //for (int i = 0; i < n; i++) { for (int j = 0; j < 2; j++) for (int k = 0; k < 2; k++) printf("dp[%d][%d][%d] = %d\n", i + 1, j, k, dp[i][j][k]); puts(""); }
    return 0;
}

Subtask #1
5.0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 296 KB Output is correct
2 Correct 1 ms 296 KB Output is correct
3 Correct 0 ms 212 KB Output is correct
4 Correct 1 ms 212 KB Output is correct
5 Correct 1 ms 212 KB Output is correct

Subtask #2
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 296 KB Output is correct
2 Correct 1 ms 296 KB Output is correct
3 Correct 0 ms 212 KB Output is correct
4 Correct 1 ms 212 KB Output is correct
5 Correct 1 ms 212 KB Output is correct
6 Correct 1 ms 212 KB Output is correct
7 Correct 1 ms 212 KB Output is correct
8 Correct 1 ms 212 KB Output is correct
9 Correct 1 ms 212 KB Output is correct
10 Correct 1 ms 212 KB Output is correct
11 Correct 1 ms 300 KB Output is correct
12 Correct 1 ms 300 KB Output is correct
13 Correct 0 ms 300 KB Output is correct
14 Correct 1 ms 212 KB Output is correct
15 Correct 1 ms 212 KB Output is correct
16 Correct 0 ms 212 KB Output is correct

Subtask #3
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 122 ms 26828 KB Output is correct
2 Correct 119 ms 26556 KB Output is correct
3 Correct 125 ms 27068 KB Output is correct

Subtask #4
40.0 / 40.0

# Verdict Execution time Memory Grader output
1 Correct 118 ms 26828 KB Output is correct
2 Correct 115 ms 26560 KB Output is correct
3 Correct 128 ms 27016 KB Output is correct
4 Correct 110 ms 20024 KB Output is correct
5 Correct 124 ms 21836 KB Output is correct
6 Correct 124 ms 22340 KB Output is correct
7 Correct 1 ms 340 KB Output is correct
8 Correct 39 ms 7612 KB Output is correct
9 Correct 120 ms 21960 KB Output is correct
10 Correct 133 ms 22540 KB Output is correct
11 Correct 121 ms 22148 KB Output is correct
12 Correct 125 ms 22784 KB Output is correct
13 Correct 113 ms 21004 KB Output is correct
14 Correct 124 ms 22292 KB Output is correct

Subtask #5
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 296 KB Output is correct
2 Correct 1 ms 296 KB Output is correct
3 Correct 0 ms 212 KB Output is correct
4 Correct 1 ms 212 KB Output is correct
5 Correct 1 ms 212 KB Output is correct
6 Correct 1 ms 212 KB Output is correct
7 Correct 1 ms 212 KB Output is correct
8 Correct 1 ms 212 KB Output is correct
9 Correct 1 ms 212 KB Output is correct
10 Correct 1 ms 212 KB Output is correct
11 Correct 1 ms 300 KB Output is correct
12 Correct 1 ms 300 KB Output is correct
13 Correct 0 ms 300 KB Output is correct
14 Correct 1 ms 212 KB Output is correct
15 Correct 1 ms 212 KB Output is correct
16 Correct 0 ms 212 KB Output is correct
17 Correct 122 ms 26828 KB Output is correct
18 Correct 119 ms 26556 KB Output is correct
19 Correct 125 ms 27068 KB Output is correct
20 Correct 118 ms 26828 KB Output is correct
21 Correct 115 ms 26560 KB Output is correct
22 Correct 128 ms 27016 KB Output is correct
23 Correct 110 ms 20024 KB Output is correct
24 Correct 124 ms 21836 KB Output is correct
25 Correct 124 ms 22340 KB Output is correct
26 Correct 1 ms 340 KB Output is correct
27 Correct 39 ms 7612 KB Output is correct
28 Correct 120 ms 21960 KB Output is correct
29 Correct 133 ms 22540 KB Output is correct
30 Correct 121 ms 22148 KB Output is correct
31 Correct 125 ms 22784 KB Output is correct
32 Correct 113 ms 21004 KB Output is correct
33 Correct 124 ms 22292 KB Output is correct
34 Correct 1 ms 340 KB Output is correct
35 Correct 0 ms 340 KB Output is correct
36 Correct 1 ms 212 KB Output is correct
37 Correct 0 ms 212 KB Output is correct
38 Correct 1 ms 296 KB Output is correct
39 Correct 1 ms 212 KB Output is correct
40 Correct 0 ms 212 KB Output is correct
41 Correct 1 ms 300 KB Output is correct
42 Correct 1 ms 212 KB Output is correct
43 Correct 0 ms 212 KB Output is correct
44 Correct 0 ms 212 KB Output is correct
45 Correct 122 ms 26836 KB Output is correct
46 Correct 111 ms 26576 KB Output is correct
47 Correct 131 ms 27172 KB Output is correct
48 Correct 117 ms 20000 KB Output is correct
49 Correct 117 ms 21928 KB Output is correct
50 Correct 123 ms 22500 KB Output is correct
51 Correct 1 ms 340 KB Output is correct
52 Correct 42 ms 7504 KB Output is correct
53 Correct 117 ms 22064 KB Output is correct
54 Correct 125 ms 22348 KB Output is correct
55 Correct 119 ms 22156 KB Output is correct
56 Correct 119 ms 22768 KB Output is correct
57 Correct 120 ms 21016 KB Output is correct
58 Correct 124 ms 22280 KB Output is correct
59 Correct 36 ms 7600 KB Output is correct
60 Correct 106 ms 20052 KB Output is correct
61 Correct 118 ms 21864 KB Output is correct
62 Correct 119 ms 22388 KB Output is correct
63 Correct 123 ms 22348 KB Output is correct
64 Correct 120 ms 22348 KB Output is correct
65 Correct 123 ms 22936 KB Output is correct
66 Correct 125 ms 22860 KB Output is correct
67 Correct 176 ms 27648 KB Output is correct
68 Correct 165 ms 27460 KB Output is correct
69 Correct 180 ms 27396 KB Output is correct
70 Correct 169 ms 27464 KB Output is correct