oj.uz

Submission #873905

# Submission time Handle Problem Language Result Execution time Memory
873905 2023-11-16T02:39:00 Z noiaint The Xana coup (BOI21_xanadu) C++17
100 / 100
 68 ms 42992 KB 
#include <bits/stdc++.h>

using namespace std;

#define file ""

#define mp make_pair
#define fi first
#define se second
#define all(x) x.begin(), x.end()

#define getbit(x, i) (((x) >> (i)) & 1)
#define bit(x) (1LL << (x))
#define popcount __builtin_popcountll

mt19937_64 rd(chrono::steady_clock::now().time_since_epoch().count());
int rand(int l, int r) {
    return l + rd() % (r - l + 1);
}

const int N = 1e6 + 5;
const int mod = (int)1e9 + 7; // 998244353;
const int lg = 25; // lg + 1
const int oo = 1e9;
const long long ooo = 1e18;

template<class X, class Y> bool mini(X &a, Y b) {
    return a > b ? (a = b, true) : false;
}
template<class X, class Y> bool maxi(X &a, Y b) {
    return a < b ? (a = b, true) : false;
}
void add(int &a, int b) {
    a += b;
    if (a >= mod) a -= mod;
    if (a < 0) a += mod;
}

int n;
vector<int> adj[N];
int state[N];

int f[N][2][2];

/*
f[u][i][j] : minimum number of moves to turn off subtree u
i = 0/1 if we toggle p
j = 0/1 if we toggle u
*/

void dfs(int u, int p) {
    for (int i = 0; i < 2; ++i) {
        f[u][i][state[u] ^ i] = i;
        f[u][i][state[u] ^ i ^ 1] = oo;
    }

    for (int v : adj[u]) if (v != p) {
        dfs(v, u);

        for (int i = 0; i < 2; ++i) {
            int even = f[u][i][0];
            int odd = f[u][i][1];
            
            f[u][i][0] = min({oo, even + f[v][0][i], odd + f[v][1][i]});
            f[u][i][1] = min({oo, even + f[v][1][i], odd + f[v][0][i]});
        }

    }
}

int main() {
    ios::sync_with_stdio(false);
    cin.tie(0);

    // freopen(file".inp", "r", stdin);
    // freopen(file".out", "w", stdout);

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

    dfs(1, 0);

    int ans = min(f[1][0][0], f[1][1][0]);
    if (ans == oo) return cout << "impossible", 0;
    cout << ans;

    return 0;
}

/*

*/

Subtask #1
5.0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 7 ms 26716 KB Output is correct
2 Correct 6 ms 26836 KB Output is correct
3 Correct 6 ms 26716 KB Output is correct
4 Correct 6 ms 26716 KB Output is correct
5 Correct 6 ms 26716 KB Output is correct

Subtask #2
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 7 ms 26716 KB Output is correct
2 Correct 6 ms 26836 KB Output is correct
3 Correct 6 ms 26716 KB Output is correct
4 Correct 6 ms 26716 KB Output is correct
5 Correct 6 ms 26716 KB Output is correct
6 Correct 7 ms 26716 KB Output is correct
7 Correct 6 ms 26716 KB Output is correct
8 Correct 6 ms 26716 KB Output is correct
9 Correct 6 ms 26844 KB Output is correct
10 Correct 6 ms 26716 KB Output is correct
11 Correct 7 ms 26716 KB Output is correct
12 Correct 6 ms 26916 KB Output is correct
13 Correct 8 ms 26716 KB Output is correct
14 Correct 7 ms 26716 KB Output is correct
15 Correct 6 ms 26800 KB Output is correct
16 Correct 7 ms 26716 KB Output is correct

Subtask #3
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 53 ms 42744 KB Output is correct
2 Correct 44 ms 42588 KB Output is correct
3 Correct 54 ms 42836 KB Output is correct

Subtask #4
40.0 / 40.0

# Verdict Execution time Memory Grader output
1 Correct 45 ms 42836 KB Output is correct
2 Correct 68 ms 42760 KB Output is correct
3 Correct 57 ms 42892 KB Output is correct
4 Correct 52 ms 33128 KB Output is correct
5 Correct 53 ms 33516 KB Output is correct
6 Correct 52 ms 33628 KB Output is correct
7 Correct 6 ms 26716 KB Output is correct
8 Correct 17 ms 30556 KB Output is correct
9 Correct 41 ms 33620 KB Output is correct
10 Correct 53 ms 33712 KB Output is correct
11 Correct 51 ms 34136 KB Output is correct
12 Correct 42 ms 34392 KB Output is correct
13 Correct 46 ms 33144 KB Output is correct
14 Correct 42 ms 33452 KB Output is correct

Subtask #5
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 7 ms 26716 KB Output is correct
2 Correct 6 ms 26836 KB Output is correct
3 Correct 6 ms 26716 KB Output is correct
4 Correct 6 ms 26716 KB Output is correct
5 Correct 6 ms 26716 KB Output is correct
6 Correct 7 ms 26716 KB Output is correct
7 Correct 6 ms 26716 KB Output is correct
8 Correct 6 ms 26716 KB Output is correct
9 Correct 6 ms 26844 KB Output is correct
10 Correct 6 ms 26716 KB Output is correct
11 Correct 7 ms 26716 KB Output is correct
12 Correct 6 ms 26916 KB Output is correct
13 Correct 8 ms 26716 KB Output is correct
14 Correct 7 ms 26716 KB Output is correct
15 Correct 6 ms 26800 KB Output is correct
16 Correct 7 ms 26716 KB Output is correct
17 Correct 53 ms 42744 KB Output is correct
18 Correct 44 ms 42588 KB Output is correct
19 Correct 54 ms 42836 KB Output is correct
20 Correct 45 ms 42836 KB Output is correct
21 Correct 68 ms 42760 KB Output is correct
22 Correct 57 ms 42892 KB Output is correct
23 Correct 52 ms 33128 KB Output is correct
24 Correct 53 ms 33516 KB Output is correct
25 Correct 52 ms 33628 KB Output is correct
26 Correct 6 ms 26716 KB Output is correct
27 Correct 17 ms 30556 KB Output is correct
28 Correct 41 ms 33620 KB Output is correct
29 Correct 53 ms 33712 KB Output is correct
30 Correct 51 ms 34136 KB Output is correct
31 Correct 42 ms 34392 KB Output is correct
32 Correct 46 ms 33144 KB Output is correct
33 Correct 42 ms 33452 KB Output is correct
34 Correct 6 ms 26716 KB Output is correct
35 Correct 6 ms 26716 KB Output is correct
36 Correct 6 ms 26716 KB Output is correct
37 Correct 7 ms 26716 KB Output is correct
38 Correct 7 ms 26972 KB Output is correct
39 Correct 6 ms 26716 KB Output is correct
40 Correct 7 ms 26916 KB Output is correct
41 Correct 7 ms 26716 KB Output is correct
42 Correct 6 ms 26716 KB Output is correct
43 Correct 7 ms 26716 KB Output is correct
44 Correct 6 ms 26716 KB Output is correct
45 Correct 50 ms 42692 KB Output is correct
46 Correct 61 ms 42568 KB Output is correct
47 Correct 46 ms 42992 KB Output is correct
48 Correct 38 ms 33116 KB Output is correct
49 Correct 50 ms 33516 KB Output is correct
50 Correct 54 ms 33428 KB Output is correct
51 Correct 7 ms 26716 KB Output is correct
52 Correct 19 ms 30640 KB Output is correct
53 Correct 49 ms 33620 KB Output is correct
54 Correct 54 ms 33640 KB Output is correct
55 Correct 46 ms 34132 KB Output is correct
56 Correct 49 ms 34292 KB Output is correct
57 Correct 43 ms 33212 KB Output is correct
58 Correct 46 ms 33604 KB Output is correct
59 Correct 18 ms 30556 KB Output is correct
60 Correct 44 ms 33204 KB Output is correct
61 Correct 48 ms 33364 KB Output is correct
62 Correct 38 ms 33708 KB Output is correct
63 Correct 37 ms 33472 KB Output is correct
64 Correct 39 ms 33628 KB Output is correct
65 Correct 48 ms 34228 KB Output is correct
66 Correct 54 ms 34132 KB Output is correct
67 Correct 47 ms 33996 KB Output is correct
68 Correct 34 ms 33956 KB Output is correct
69 Correct 36 ms 33840 KB Output is correct
70 Correct 32 ms 33996 KB Output is correct