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Submission #399130

# Submission time Handle Problem Language Result Execution time Memory
399130 2021-05-05T10:47:04 Z Jarif_Rahman The Xana coup (BOI21_xanadu) C++17
100 / 100
 110 ms 28648 KB 
#include <bits/stdc++.h>
#define pb push_back
#define f first
#define sc second
using namespace std;
typedef long long int ll;
typedef string str;
const ll inf = 1e9;

int n;

vector<vector<int>> v;
vector<vector<vector<ll>>> dp;
vector<int> state;

void dfs(int nd, int ss){
    if(v[nd].size() == 1 && ss != -1){
        dp[nd][0][0] = (state[nd]?inf:0);
        dp[nd][0][1] = (state[nd]?1:inf);
        dp[nd][1][0] = (state[nd]?0:inf);
        dp[nd][1][1] = (state[nd]?inf:1);
        return;
    }
    for(int x: v[nd]) if(x != ss) dfs(x, nd);

    dp[nd][0][1] = 1;
    dp[nd][1][1] = 1;

    int cnt = 0;
    ll mn = inf;
    for(int x: v[nd]) if(x != ss){
        dp[nd][0][0] += min(dp[x][0][0], dp[x][0][1]);
        dp[nd][1][0] += min(dp[x][0][0], dp[x][0][1]);
        if(dp[x][0][0] > dp[x][0][1]) cnt++;
        mn = min(mn, abs(dp[x][0][0]-dp[x][0][1]));
    }
    if(state[nd]){
        if(cnt%2 == 0) dp[nd][0][0]+=mn;
        else dp[nd][1][0]+=mn;
    }
    else{
        if(cnt%2 == 0) dp[nd][1][0]+=mn;
        else dp[nd][0][0]+=mn;
    }

    cnt = 0;
    mn = inf;
    for(int x: v[nd]) if(x != ss){
        dp[nd][0][1] += min(dp[x][1][0], dp[x][1][1]);
        dp[nd][1][1] += min(dp[x][1][0], dp[x][1][1]);
        if(dp[x][1][0] > dp[x][1][1]) cnt++;
        mn = min(mn, abs(dp[x][1][0]-dp[x][1][1]));
    }
    if(!state[nd]){
        if(cnt%2 == 0) dp[nd][0][1]+=mn;
        else dp[nd][1][1]+=mn;
    }
    else{
        if(cnt%2 == 0) dp[nd][1][1]+=mn;
        else dp[nd][0][1]+=mn;
    }
    dp[nd][0][0] = min(dp[nd][0][0], inf);
    dp[nd][1][0] = min(dp[nd][1][0], inf);
    dp[nd][0][1] = min(dp[nd][0][1], inf);
    dp[nd][1][1] = min(dp[nd][1][1], inf);
}

int main(){
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cin >> n;
    v.resize(n);
    state.resize(n);
    dp.assign(n, vector<vector<ll>>(2, vector<ll>(2, 0)));
    for(int i = 0; i < n-1; i++){
        int a, b; cin >> a >> b; a--, b--;
        v[a].pb(b);
        v[b].pb(a);
    }
    for(int &x: state) cin >> x;
    dfs(0, -1);
    ll 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

# Verdict Execution time Memory Grader output
1 Correct 1 ms 204 KB Output is correct
2 Correct 1 ms 204 KB Output is correct
3 Correct 1 ms 204 KB Output is correct
4 Correct 1 ms 204 KB Output is correct
5 Correct 1 ms 204 KB Output is correct

Subtask #2
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 204 KB Output is correct
2 Correct 1 ms 204 KB Output is correct
3 Correct 1 ms 204 KB Output is correct
4 Correct 1 ms 204 KB Output is correct
5 Correct 1 ms 204 KB Output is correct
6 Correct 1 ms 204 KB Output is correct
7 Correct 1 ms 204 KB Output is correct
8 Correct 1 ms 204 KB Output is correct
9 Correct 1 ms 204 KB Output is correct
10 Correct 1 ms 204 KB Output is correct
11 Correct 1 ms 204 KB Output is correct
12 Correct 1 ms 204 KB Output is correct
13 Correct 1 ms 204 KB Output is correct
14 Correct 1 ms 204 KB Output is correct
15 Correct 1 ms 204 KB Output is correct
16 Correct 1 ms 204 KB Output is correct

Subtask #3
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 77 ms 27152 KB Output is correct
2 Correct 80 ms 28100 KB Output is correct
3 Correct 91 ms 28648 KB Output is correct

Subtask #4
40.0 / 40.0

# Verdict Execution time Memory Grader output
1 Correct 80 ms 27104 KB Output is correct
2 Correct 79 ms 28100 KB Output is correct
3 Correct 93 ms 28584 KB Output is correct
4 Correct 89 ms 19996 KB Output is correct
5 Correct 101 ms 21928 KB Output is correct
6 Correct 103 ms 22292 KB Output is correct
7 Correct 1 ms 332 KB Output is correct
8 Correct 28 ms 7652 KB Output is correct
9 Correct 103 ms 22084 KB Output is correct
10 Correct 106 ms 22364 KB Output is correct
11 Correct 109 ms 22236 KB Output is correct
12 Correct 106 ms 22888 KB Output is correct
13 Correct 91 ms 21020 KB Output is correct
14 Correct 99 ms 22388 KB Output is correct

Subtask #5
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 204 KB Output is correct
2 Correct 1 ms 204 KB Output is correct
3 Correct 1 ms 204 KB Output is correct
4 Correct 1 ms 204 KB Output is correct
5 Correct 1 ms 204 KB Output is correct
6 Correct 1 ms 204 KB Output is correct
7 Correct 1 ms 204 KB Output is correct
8 Correct 1 ms 204 KB Output is correct
9 Correct 1 ms 204 KB Output is correct
10 Correct 1 ms 204 KB Output is correct
11 Correct 1 ms 204 KB Output is correct
12 Correct 1 ms 204 KB Output is correct
13 Correct 1 ms 204 KB Output is correct
14 Correct 1 ms 204 KB Output is correct
15 Correct 1 ms 204 KB Output is correct
16 Correct 1 ms 204 KB Output is correct
17 Correct 77 ms 27152 KB Output is correct
18 Correct 80 ms 28100 KB Output is correct
19 Correct 91 ms 28648 KB Output is correct
20 Correct 80 ms 27104 KB Output is correct
21 Correct 79 ms 28100 KB Output is correct
22 Correct 93 ms 28584 KB Output is correct
23 Correct 89 ms 19996 KB Output is correct
24 Correct 101 ms 21928 KB Output is correct
25 Correct 103 ms 22292 KB Output is correct
26 Correct 1 ms 332 KB Output is correct
27 Correct 28 ms 7652 KB Output is correct
28 Correct 103 ms 22084 KB Output is correct
29 Correct 106 ms 22364 KB Output is correct
30 Correct 109 ms 22236 KB Output is correct
31 Correct 106 ms 22888 KB Output is correct
32 Correct 91 ms 21020 KB Output is correct
33 Correct 99 ms 22388 KB Output is correct
34 Correct 1 ms 204 KB Output is correct
35 Correct 1 ms 204 KB Output is correct
36 Correct 1 ms 204 KB Output is correct
37 Correct 1 ms 204 KB Output is correct
38 Correct 1 ms 312 KB Output is correct
39 Correct 1 ms 204 KB Output is correct
40 Correct 1 ms 204 KB Output is correct
41 Correct 1 ms 204 KB Output is correct
42 Correct 1 ms 204 KB Output is correct
43 Correct 1 ms 316 KB Output is correct
44 Correct 1 ms 204 KB Output is correct
45 Correct 79 ms 28412 KB Output is correct
46 Correct 78 ms 28168 KB Output is correct
47 Correct 82 ms 28612 KB Output is correct
48 Correct 97 ms 20040 KB Output is correct
49 Correct 99 ms 21832 KB Output is correct
50 Correct 101 ms 22340 KB Output is correct
51 Correct 1 ms 332 KB Output is correct
52 Correct 28 ms 7560 KB Output is correct
53 Correct 110 ms 22040 KB Output is correct
54 Correct 109 ms 22576 KB Output is correct
55 Correct 103 ms 22208 KB Output is correct
56 Correct 110 ms 22980 KB Output is correct
57 Correct 91 ms 20896 KB Output is correct
58 Correct 99 ms 22360 KB Output is correct
59 Correct 28 ms 7628 KB Output is correct
60 Correct 89 ms 20036 KB Output is correct
61 Correct 104 ms 21940 KB Output is correct
62 Correct 101 ms 22476 KB Output is correct
63 Correct 101 ms 22396 KB Output is correct
64 Correct 106 ms 22372 KB Output is correct
65 Correct 84 ms 22832 KB Output is correct
66 Correct 85 ms 22944 KB Output is correct
67 Correct 88 ms 22792 KB Output is correct
68 Correct 93 ms 22816 KB Output is correct
69 Correct 91 ms 22716 KB Output is correct
70 Correct 91 ms 22700 KB Output is correct