oj.uz

Submission #894608

# Submission time Handle Problem Language Result Execution time Memory
894608 2023-12-28T14:20:56 Z esomer The Xana coup (BOI21_xanadu) C++17
100 / 100
 73 ms 15820 KB 
#include<bits/stdc++.h>
 
using namespace std;

#define int long long

const int N = 100000;
const int INF = 1e11;

vector<int> adj[N];
int dp[4][N]; //0 - I don't toggle. 1 - I toggle. 2, 3 - same but the camera is not off.
int initial[N];

void get0(int x, int p){
    if(initial[x] == 0){
        int ans = 0;
        vector<int> change;
        for(int node : adj[x]){
            if(node != p){
                ans += dp[0][node];
                change.push_back(dp[1][node] - dp[0][node]);
            }
        }
        sort(change.begin(), change.end());
        int mn = 0;
        int curr = 0;
        for(int i = 0; i + 1 < (int)change.size(); i += 2){
            curr += change[i] + change[i+1];
            mn = min(mn, curr);
        }
        dp[0][x] = ans + mn;
    }else{
        dp[0][x] = INF;
        int ans = 0;
        vector<int> change;
        for(int node : adj[x]){
            if(node != p){
                ans += dp[0][node];
                change.push_back(dp[1][node] - dp[0][node]);
            }
        }
        if(change.empty()) return;
        sort(change.begin(), change.end());
        int mn = change[0];
        int curr = change[0];
        for(int i = 1; i + 1 < (int)change.size(); i += 2){
            curr += change[i] + change[i+1];
            mn = min(mn, curr);
        }
        dp[0][x] = ans + mn;
    }
}

void get1(int x, int p){
    if(initial[x] == 1){
        int ans = 1;
        vector<int> change;
        for(int node : adj[x]){
            if(node != p){
                ans += dp[2][node];
                change.push_back(dp[3][node] - dp[2][node]);
            }
        }
        sort(change.begin(), change.end());
        int mn = 0;
        int curr = 0;
        for(int i = 0; i + 1 < (int)change.size(); i += 2){
            curr += change[i] + change[i+1];
            mn = min(mn, curr);
        }
        dp[1][x] = ans + mn;
    }else{
        dp[1][x] = INF;
        int ans = 1;
        vector<int> change;
        for(int node : adj[x]){
            if(node != p){
                ans += dp[2][node];
                change.push_back(dp[3][node] - dp[2][node]);
            }
        }
        if(change.empty()) return;
        sort(change.begin(), change.end());
        int mn = change[0];
        int curr = change[0];
        for(int i = 1; i + 1 < (int)change.size(); i += 2){
            curr += change[i] + change[i+1];
            mn = min(mn, curr);
        }
        dp[1][x] = ans + mn;
    }
}

void get2(int x, int p){
    if(initial[x] == 1){
        int ans = 0;
        vector<int> change;
        for(int node : adj[x]){
            if(node != p){
                ans += dp[0][node];
                change.push_back(dp[1][node] - dp[0][node]);
            }
        }
        sort(change.begin(), change.end());
        int mn = 0;
        int curr = 0;
        for(int i = 0; i + 1 < (int)change.size(); i += 2){
            curr += change[i] + change[i+1];
            mn = min(mn, curr);
        }
        dp[2][x] = ans + mn;
    }else{
        dp[2][x] = INF;
        int ans = 0;
        vector<int> change;
        for(int node : adj[x]){
            if(node != p){
                ans += dp[0][node];
                change.push_back(dp[1][node] - dp[0][node]);
            }
        }
        if(change.empty()) return;
        sort(change.begin(), change.end());
        int mn = change[0];
        int curr = change[0];
        for(int i = 1; i + 1 < (int)change.size(); i += 2){
            curr += change[i] + change[i+1];
            mn = min(mn, curr);
        }
        dp[2][x] = ans + mn;
    }
}

void get3(int x, int p){
    if(initial[x] == 0){
        int ans = 1;
        vector<int> change;
        for(int node : adj[x]){
            if(node != p){
                ans += dp[2][node];
                change.push_back(dp[3][node] - dp[2][node]);
            }
        }
        sort(change.begin(), change.end());
        int mn = 0;
        int curr = 0;
        for(int i = 0; i + 1 < (int)change.size(); i += 2){
            curr += change[i] + change[i+1];
            mn = min(mn, curr);
        }
        dp[3][x] = ans + mn;
    }else{
        dp[3][x] = INF;
        int ans = 1;
        vector<int> change;
        for(int node : adj[x]){
            if(node != p){
                ans += dp[2][node];
                change.push_back(dp[3][node] - dp[2][node]);
            }
        }
        if(change.empty()) return;
        sort(change.begin(), change.end());
        int mn = change[0];
        int curr = change[0];
        for(int i = 1; i + 1 < (int)change.size(); i += 2){
            curr += change[i] + change[i+1];
            mn = min(mn, curr);
        }
        dp[3][x] = ans + mn;
    }
}

void DFS(int x, int p){
    for(int node : adj[x]){
        if(node != p) DFS(node, x);
    }
    get0(x, p);
    get1(x, p);
    get2(x, p);
    get3(x, p);
}

signed main(){
    ios_base::sync_with_stdio(0);
    cin.tie(0);

    int n; cin >> n;
    for(int i = 0; i < n - 1; i++){
        int a, b; cin >> a >> b; a--; b--;
        adj[a].push_back(b);
        adj[b].push_back(a);
    }
    for(int i = 0; i < n; i++) cin >> initial[i];
    DFS(0, -1);
    if(min(dp[0][0], dp[1][0]) >= 1e6) cout << "impossible\n";
    else cout << min(dp[0][0], dp[1][0]) << "\n";
}

Subtask #1
5.0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 6492 KB Output is correct
2 Correct 2 ms 6536 KB Output is correct
3 Correct 2 ms 6492 KB Output is correct
4 Correct 2 ms 6492 KB Output is correct
5 Correct 2 ms 6488 KB Output is correct

Subtask #2
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 6492 KB Output is correct
2 Correct 2 ms 6536 KB Output is correct
3 Correct 2 ms 6492 KB Output is correct
4 Correct 2 ms 6492 KB Output is correct
5 Correct 2 ms 6488 KB Output is correct
6 Correct 2 ms 6496 KB Output is correct
7 Correct 2 ms 6488 KB Output is correct
8 Correct 2 ms 6492 KB Output is correct
9 Correct 1 ms 6492 KB Output is correct
10 Correct 2 ms 6492 KB Output is correct
11 Correct 2 ms 6492 KB Output is correct
12 Correct 2 ms 6544 KB Output is correct
13 Correct 1 ms 6488 KB Output is correct
14 Correct 1 ms 6492 KB Output is correct
15 Correct 2 ms 6544 KB Output is correct
16 Correct 2 ms 6492 KB Output is correct

Subtask #3
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 46 ms 15820 KB Output is correct
2 Correct 64 ms 15700 KB Output is correct
3 Correct 43 ms 15708 KB Output is correct

Subtask #4
40.0 / 40.0

# Verdict Execution time Memory Grader output
1 Correct 43 ms 15816 KB Output is correct
2 Correct 43 ms 15708 KB Output is correct
3 Correct 43 ms 15812 KB Output is correct
4 Correct 45 ms 11348 KB Output is correct
5 Correct 49 ms 11868 KB Output is correct
6 Correct 50 ms 12060 KB Output is correct
7 Correct 2 ms 6492 KB Output is correct
8 Correct 21 ms 8384 KB Output is correct
9 Correct 44 ms 11612 KB Output is correct
10 Correct 46 ms 11768 KB Output is correct
11 Correct 45 ms 11856 KB Output is correct
12 Correct 46 ms 11856 KB Output is correct
13 Correct 73 ms 11844 KB Output is correct
14 Correct 51 ms 12112 KB Output is correct

Subtask #5
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 6492 KB Output is correct
2 Correct 2 ms 6536 KB Output is correct
3 Correct 2 ms 6492 KB Output is correct
4 Correct 2 ms 6492 KB Output is correct
5 Correct 2 ms 6488 KB Output is correct
6 Correct 2 ms 6496 KB Output is correct
7 Correct 2 ms 6488 KB Output is correct
8 Correct 2 ms 6492 KB Output is correct
9 Correct 1 ms 6492 KB Output is correct
10 Correct 2 ms 6492 KB Output is correct
11 Correct 2 ms 6492 KB Output is correct
12 Correct 2 ms 6544 KB Output is correct
13 Correct 1 ms 6488 KB Output is correct
14 Correct 1 ms 6492 KB Output is correct
15 Correct 2 ms 6544 KB Output is correct
16 Correct 2 ms 6492 KB Output is correct
17 Correct 46 ms 15820 KB Output is correct
18 Correct 64 ms 15700 KB Output is correct
19 Correct 43 ms 15708 KB Output is correct
20 Correct 43 ms 15816 KB Output is correct
21 Correct 43 ms 15708 KB Output is correct
22 Correct 43 ms 15812 KB Output is correct
23 Correct 45 ms 11348 KB Output is correct
24 Correct 49 ms 11868 KB Output is correct
25 Correct 50 ms 12060 KB Output is correct
26 Correct 2 ms 6492 KB Output is correct
27 Correct 21 ms 8384 KB Output is correct
28 Correct 44 ms 11612 KB Output is correct
29 Correct 46 ms 11768 KB Output is correct
30 Correct 45 ms 11856 KB Output is correct
31 Correct 46 ms 11856 KB Output is correct
32 Correct 73 ms 11844 KB Output is correct
33 Correct 51 ms 12112 KB Output is correct
34 Correct 1 ms 6492 KB Output is correct
35 Correct 2 ms 6492 KB Output is correct
36 Correct 1 ms 6488 KB Output is correct
37 Correct 1 ms 6492 KB Output is correct
38 Correct 2 ms 6492 KB Output is correct
39 Correct 2 ms 6304 KB Output is correct
40 Correct 2 ms 6744 KB Output is correct
41 Correct 2 ms 6492 KB Output is correct
42 Correct 2 ms 6492 KB Output is correct
43 Correct 2 ms 6356 KB Output is correct
44 Correct 1 ms 6492 KB Output is correct
45 Correct 42 ms 15744 KB Output is correct
46 Correct 42 ms 15700 KB Output is correct
47 Correct 44 ms 15628 KB Output is correct
48 Correct 48 ms 11356 KB Output is correct
49 Correct 54 ms 11864 KB Output is correct
50 Correct 48 ms 11856 KB Output is correct
51 Correct 2 ms 6492 KB Output is correct
52 Correct 16 ms 8348 KB Output is correct
53 Correct 44 ms 11648 KB Output is correct
54 Correct 59 ms 11604 KB Output is correct
55 Correct 45 ms 11864 KB Output is correct
56 Correct 45 ms 11860 KB Output is correct
57 Correct 44 ms 11868 KB Output is correct
58 Correct 47 ms 12376 KB Output is correct
59 Correct 16 ms 8280 KB Output is correct
60 Correct 42 ms 11172 KB Output is correct
61 Correct 47 ms 11572 KB Output is correct
62 Correct 47 ms 11612 KB Output is correct
63 Correct 47 ms 11808 KB Output is correct
64 Correct 49 ms 11720 KB Output is correct
65 Correct 39 ms 12164 KB Output is correct
66 Correct 38 ms 12156 KB Output is correct
67 Correct 37 ms 13756 KB Output is correct
68 Correct 40 ms 13776 KB Output is correct
69 Correct 42 ms 13704 KB Output is correct
70 Correct 41 ms 13736 KB Output is correct