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Submission #696189

# Submission time Handle Problem Language Result Execution time Memory
696189 2023-02-05T18:45:30 Z RaulAndrei01 The Xana coup (BOI21_xanadu) C++17
30 / 100
 102 ms 18372 KB 
#include <iostream>
#include <bits/stdc++.h>
#include <vector>

using namespace std;
using ll = long long;
const int nmax = 1e5 + 9;
const ll inf = 1e7;
vector<int> adj[nmax];
bool on[nmax];

ll dp[2][2][nmax];

void dfs (int nod = 1, int par = 0)
{
    int temp[2][2];

    temp[0][0] = 0;
    temp[1][0] = 0;

    temp[0][1] = inf;
    temp[1][1] = inf;
    
    for (auto to : adj[nod])
    {
        if (to == par) continue;
        
        dfs (to , nod);
        int t[2][2];
        
        t[0][0] = min(temp[0][0] + dp[0][0][to] , temp[0][1] + dp[0][1][to]);
        t[1][0] = min (temp[1][0] + dp[1][0][to] , temp[1][1] + dp[1][1][to]);
        t[0][1] = min(temp[0][1] + dp[0][0][to] , temp[0][0] + dp[0][1][to]);
        t[1][1] = min(temp[1][0] + dp[1][1][to] , temp[1][1] + dp[1][0][to]);
        
        

        for (int i = 0; i < 2; i++)
          for (int j = 0; j < 2; j++)
            temp[i][j] = t[i][j];
    }
    if (on[nod])
    {
        dp[0][0][nod] = temp[0][1];
        dp[0][1][nod] = 1 + temp[1][0];
        dp[1][0][nod] = temp[0][0];
        dp[1][1][nod] = 1 + temp[1][1];
    }
    else {
        dp[0][0][nod] = temp[0][0];
        dp[0][1][nod] = 1 + temp[1][1];
        dp[1][0][nod] = temp[0][1];
        dp[1][1][nod] = 1 + temp[1][0];
    }
 //   cout << nod << '\n';
   // cout << temp[0][0] << ' ' << temp[0][1] << ' ' << temp[1][0] << ' ' << temp[1][1] << '\n';
  //  cout << dp[0][0][nod] << ' ' << dp[0][1][nod] << ' ' << dp[1][0][nod] <<
  //  ' '<< dp[1][1][nod];
  //  cout << '\n';
}

int main ()
{
    int n; cin >> n; 
    for (int i = 1; i < n; i++)
    {
        int x, y; cin >> x >> y;
        adj[x].push_back(y);
        adj[y].push_back(x);
    }
    for (int i = 1; i <= n; i++)
    {
        cin >> on[i];
    }
    
    dfs();
    if (min(dp[0][1][1] , dp[0][0][1]) >= inf) cout << "impossible\n";
    else cout << min(dp[0][1][1] , dp[0][0][1]);
}

Subtask #1
5.0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 2644 KB Output is correct
2 Correct 1 ms 2644 KB Output is correct
3 Correct 2 ms 2656 KB Output is correct
4 Correct 1 ms 2644 KB Output is correct
5 Correct 1 ms 2644 KB Output is correct

Subtask #2
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 2644 KB Output is correct
2 Correct 1 ms 2644 KB Output is correct
3 Correct 2 ms 2656 KB Output is correct
4 Correct 1 ms 2644 KB Output is correct
5 Correct 1 ms 2644 KB Output is correct
6 Correct 2 ms 2644 KB Output is correct
7 Correct 2 ms 2644 KB Output is correct
8 Correct 1 ms 2644 KB Output is correct
9 Correct 2 ms 2644 KB Output is correct
10 Correct 2 ms 2644 KB Output is correct
11 Correct 1 ms 2644 KB Output is correct
12 Correct 2 ms 2644 KB Output is correct
13 Correct 1 ms 2644 KB Output is correct
14 Correct 1 ms 2644 KB Output is correct
15 Correct 2 ms 2644 KB Output is correct
16 Correct 2 ms 2644 KB Output is correct

Subtask #3
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 101 ms 18304 KB Output is correct
2 Correct 87 ms 18124 KB Output is correct
3 Correct 91 ms 18308 KB Output is correct

Subtask #4
0 / 40.0

# Verdict Execution time Memory Grader output
1 Correct 100 ms 18208 KB Output is correct
2 Correct 90 ms 18128 KB Output is correct
3 Correct 102 ms 18372 KB Output is correct
4 Incorrect 76 ms 8320 KB Output isn't correct
5 Halted 0 ms 0 KB -

Subtask #5
0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 2644 KB Output is correct
2 Correct 1 ms 2644 KB Output is correct
3 Correct 2 ms 2656 KB Output is correct
4 Correct 1 ms 2644 KB Output is correct
5 Correct 1 ms 2644 KB Output is correct
6 Correct 2 ms 2644 KB Output is correct
7 Correct 2 ms 2644 KB Output is correct
8 Correct 1 ms 2644 KB Output is correct
9 Correct 2 ms 2644 KB Output is correct
10 Correct 2 ms 2644 KB Output is correct
11 Correct 1 ms 2644 KB Output is correct
12 Correct 2 ms 2644 KB Output is correct
13 Correct 1 ms 2644 KB Output is correct
14 Correct 1 ms 2644 KB Output is correct
15 Correct 2 ms 2644 KB Output is correct
16 Correct 2 ms 2644 KB Output is correct
17 Correct 101 ms 18304 KB Output is correct
18 Correct 87 ms 18124 KB Output is correct
19 Correct 91 ms 18308 KB Output is correct
20 Correct 100 ms 18208 KB Output is correct
21 Correct 90 ms 18128 KB Output is correct
22 Correct 102 ms 18372 KB Output is correct
23 Incorrect 76 ms 8320 KB Output isn't correct
24 Halted 0 ms 0 KB -