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Submission #755359

# Submission time Handle Problem Language Result Execution time Memory
755359 2023-06-10T01:52:33 Z __Davit__ The Xana coup (BOI21_xanadu) C++17
100 / 100
 120 ms 16888 KB 
#define _CRT_SECURE_NO_WARNINGS

#include <bits/stdc++.h>

#define ll long long
#define lld long double
#define ff first
#define ss second
#define pb push_back
#define vr(v) v.begin(),v.end()
#define rv(v) v.rbegin(),v.rend()
#define Code ios_base::sync_with_stdio(false);
#define By cin.tie(NULL);
#define Davit cout.tie(NULL);

using namespace std;

vector<vector<int>> gp;
vector<int> col;

const int INF = 1e6;
ll dp[100005][2][2];

void dfs(int u, int p) {

    for (auto x: gp[u]) {
        if (x != p)dfs(x, u);
    }

    if ((int) gp[u].size() == 1 && u != 0) {//leaves
        if (col[u]) {
            dp[u][0][0] = 0;
            dp[u][1][1] = 1;
            dp[u][0][1] = dp[u][1][0] = INF;
        } else {
            dp[u][0][0] = INF;
            dp[u][1][1] = INF;
            dp[u][1][0] = 1;
            dp[u][0][1] = 0;//we count it later (during merge)
        }
        return;
    }
    ll res = 0, cnt = 0, diff = INF;
    //dp[x][0/1][0]
    for (auto x: gp[u]) {
        if (x == p)continue;
        res += min(dp[x][0][0], dp[x][1][0]);
        if (dp[x][1][0] < dp[x][0][0])cnt++;
        diff = min(diff, abs(dp[x][0][0] - dp[x][1][0]));
    }
    dp[u][0][0] = res;
    if (col[u] == cnt % 2)dp[u][0][0] += diff;
    dp[u][0][1] = res;
    if (col[u] != cnt % 2)dp[u][0][1] += diff;

    res = 0, cnt = 0, diff = INF;
    for (auto x: gp[u]) {
        if (x == p)continue;
        res += min(dp[x][0][1], dp[x][1][1]);
        if (dp[x][1][1] < dp[x][0][1])cnt++;
        diff = min(diff, abs(dp[x][0][1] - dp[x][1][1]));
    }
    res++;
    dp[u][1][0] = res;
    if (col[u] != cnt % 2)dp[u][1][0] += diff;
    dp[u][1][1] = res;
    if (col[u] == cnt % 2)dp[u][1][1] += diff;

}

int main() {
    int n;
    cin >> n;
    gp.resize(n);
    col.resize(n);
    for (int i = 0; i < n - 1; i++) {
        int u, v;
        cin >> u >> v;
        u--, v--;
        gp[u].pb(v);
        gp[v].pb(u);
    }
    for (int i = 0; i < n; i++)cin >> col[i], col[i] = !col[i];

    dfs(0, -1);

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

Subtask #1
5.0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 212 KB Output is correct
2 Correct 1 ms 212 KB Output is correct
3 Correct 1 ms 312 KB Output is correct
4 Correct 1 ms 308 KB Output is correct
5 Correct 0 ms 212 KB Output is correct

Subtask #2
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 212 KB Output is correct
2 Correct 1 ms 212 KB Output is correct
3 Correct 1 ms 312 KB Output is correct
4 Correct 1 ms 308 KB Output is correct
5 Correct 0 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 212 KB Output is correct
12 Correct 1 ms 212 KB Output is correct
13 Correct 1 ms 212 KB Output is correct
14 Correct 1 ms 212 KB Output is correct
15 Correct 1 ms 212 KB Output is correct
16 Correct 1 ms 212 KB Output is correct

Subtask #3
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 98 ms 16692 KB Output is correct
2 Correct 109 ms 16692 KB Output is correct
3 Correct 102 ms 16888 KB Output is correct

Subtask #4
40.0 / 40.0

# Verdict Execution time Memory Grader output
1 Correct 104 ms 16740 KB Output is correct
2 Correct 102 ms 16612 KB Output is correct
3 Correct 99 ms 16788 KB Output is correct
4 Correct 96 ms 9444 KB Output is correct
5 Correct 106 ms 10396 KB Output is correct
6 Correct 107 ms 10612 KB Output is correct
7 Correct 1 ms 312 KB Output is correct
8 Correct 29 ms 3660 KB Output is correct
9 Correct 112 ms 10536 KB Output is correct
10 Correct 120 ms 10604 KB Output is correct
11 Correct 96 ms 10856 KB Output is correct
12 Correct 111 ms 11220 KB Output is correct
13 Correct 84 ms 10000 KB Output is correct
14 Correct 112 ms 10572 KB Output is correct

Subtask #5
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 212 KB Output is correct
2 Correct 1 ms 212 KB Output is correct
3 Correct 1 ms 312 KB Output is correct
4 Correct 1 ms 308 KB Output is correct
5 Correct 0 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 212 KB Output is correct
12 Correct 1 ms 212 KB Output is correct
13 Correct 1 ms 212 KB Output is correct
14 Correct 1 ms 212 KB Output is correct
15 Correct 1 ms 212 KB Output is correct
16 Correct 1 ms 212 KB Output is correct
17 Correct 98 ms 16692 KB Output is correct
18 Correct 109 ms 16692 KB Output is correct
19 Correct 102 ms 16888 KB Output is correct
20 Correct 104 ms 16740 KB Output is correct
21 Correct 102 ms 16612 KB Output is correct
22 Correct 99 ms 16788 KB Output is correct
23 Correct 96 ms 9444 KB Output is correct
24 Correct 106 ms 10396 KB Output is correct
25 Correct 107 ms 10612 KB Output is correct
26 Correct 1 ms 312 KB Output is correct
27 Correct 29 ms 3660 KB Output is correct
28 Correct 112 ms 10536 KB Output is correct
29 Correct 120 ms 10604 KB Output is correct
30 Correct 96 ms 10856 KB Output is correct
31 Correct 111 ms 11220 KB Output is correct
32 Correct 84 ms 10000 KB Output is correct
33 Correct 112 ms 10572 KB Output is correct
34 Correct 1 ms 212 KB Output is correct
35 Correct 0 ms 212 KB Output is correct
36 Correct 1 ms 212 KB Output is correct
37 Correct 1 ms 304 KB Output is correct
38 Correct 1 ms 212 KB Output is correct
39 Correct 1 ms 304 KB Output is correct
40 Correct 1 ms 212 KB Output is correct
41 Correct 1 ms 212 KB Output is correct
42 Correct 1 ms 212 KB Output is correct
43 Correct 1 ms 212 KB Output is correct
44 Correct 1 ms 212 KB Output is correct
45 Correct 107 ms 16812 KB Output is correct
46 Correct 92 ms 16504 KB Output is correct
47 Correct 95 ms 16880 KB Output is correct
48 Correct 98 ms 9592 KB Output is correct
49 Correct 116 ms 10320 KB Output is correct
50 Correct 114 ms 10604 KB Output is correct
51 Correct 1 ms 340 KB Output is correct
52 Correct 28 ms 3660 KB Output is correct
53 Correct 106 ms 10412 KB Output is correct
54 Correct 92 ms 10628 KB Output is correct
55 Correct 93 ms 10820 KB Output is correct
56 Correct 95 ms 11100 KB Output is correct
57 Correct 83 ms 9884 KB Output is correct
58 Correct 88 ms 10572 KB Output is correct
59 Correct 27 ms 3708 KB Output is correct
60 Correct 87 ms 9592 KB Output is correct
61 Correct 102 ms 10492 KB Output is correct
62 Correct 119 ms 10756 KB Output is correct
63 Correct 118 ms 10656 KB Output is correct
64 Correct 117 ms 10596 KB Output is correct
65 Correct 92 ms 11104 KB Output is correct
66 Correct 93 ms 11064 KB Output is correct
67 Correct 89 ms 10964 KB Output is correct
68 Correct 89 ms 11000 KB Output is correct
69 Correct 88 ms 10936 KB Output is correct
70 Correct 88 ms 11048 KB Output is correct