oj.uz

Submission #923787

# Submission time Handle Problem Language Result Execution time Memory
923787 2024-02-07T18:48:10 Z aykhn The Xana coup (BOI21_xanadu) C++17
100 / 100
 63 ms 25428 KB 
#include <bits/stdc++.h>
// author: aykhn
using namespace std;
#define int long long
#define inf 0x3F3F3F3F

const int MXN = 1e5 + 5;

int n;
vector<int> adj[MXN];
int val[MXN], dp[MXN][2][2];

// dp[i][j][k] = j by doing k ops and ok subtree

void dfs(int a, int p)
{
    vector<int> v1;
    int f = 0;
    for (int v : adj[a])
    {
        if (v == p) continue;
        f = 1;
        dfs(v, a);
        v1.push_back(v);
    }
    if (!f)
    {
        if (!val[a]) dp[a][0][0] = 0, dp[a][0][1] = inf, dp[a][1][0] = inf, dp[a][1][1] = 1;
        else dp[a][0][0] = inf, dp[a][0][1] = 1, dp[a][1][0] = 0, dp[a][1][1] = inf;
        return;
    }
    if (!val[a])
    {
        dp[a][0][0] = 0;
        vector<int> nw;
        for (int v : v1)
        {
            dp[a][0][0] += dp[v][0][0];
            nw.push_back(dp[v][0][1] - dp[v][0][0]);
        }
        sort(nw.begin(), nw.end());
        int s = 0, mn = 0;
        for (int i = 0; i < nw.size(); i++)
        {
            s += nw[i];
            if (i % 2 == 1) mn = min(mn, s);
        }
        dp[a][0][0] += mn;
        //---
        dp[a][0][1] = 1;
        nw.clear();
        for (int v : v1)
        {
            dp[a][0][1] += dp[v][1][0];
            nw.push_back(dp[v][1][1] - dp[v][1][0]);
        }
        sort(nw.begin(), nw.end());
        s = 0, mn = inf;
        for (int i = 0; i < nw.size(); i++)
        {
            s += nw[i];
            if (i % 2 == 0) mn = min(mn, s);
        }
        dp[a][0][1] += mn;
        //---
        dp[a][1][0] = 0;
        nw.clear();
        for (int v : v1)
        {
            dp[a][1][0] += dp[v][0][0];
            nw.push_back(dp[v][0][1] - dp[v][0][0]);
        }
        sort(nw.begin(), nw.end());
        s = 0, mn = inf;
        for (int i = 0; i < nw.size(); i++)
        {
            s += nw[i];
            if (i % 2 == 0) mn = min(mn, s);
        }
        dp[a][1][0] += mn;
        //---
        dp[a][1][1] = 1;
        nw.clear();
        for (int v : v1)
        {
            dp[a][1][1] += dp[v][1][0];
            nw.push_back(dp[v][1][1] - dp[v][1][0]);
        }
        sort(nw.begin(), nw.end());
        s = 0, mn = 0;
        for (int i = 0; i < nw.size(); i++)
        {
            s += nw[i];
            if (i % 2 == 1) mn = min(mn, s);
        }
        dp[a][1][1] += mn;
    }
    else
    {
        dp[a][0][0] = 0;
        vector<int> nw;
        for (int v : v1)
        {
            dp[a][0][0] += dp[v][0][0];
            nw.push_back(dp[v][0][1] - dp[v][0][0]);
        }
        sort(nw.begin(), nw.end());
        int s = 0, mn = inf;
        for (int i = 0; i < nw.size(); i++)
        {
            s += nw[i];
            if (i % 2 == 0) mn = min(mn, s);
        }
        dp[a][0][0] += mn;
        //---
        dp[a][0][1] = 1;
        nw.clear();
        for (int v : v1)
        {
            dp[a][0][1] += dp[v][1][0];
            nw.push_back(dp[v][1][1] - dp[v][1][0]);
        }
        sort(nw.begin(), nw.end());
        s = 0, mn = 0;
        for (int i = 0; i < nw.size(); i++)
        {
            s += nw[i];
            if (i % 2 == 1) mn = min(mn, s);
        }
        dp[a][0][1] += mn;
        //---
        dp[a][1][0] = 0;
        nw.clear();
        for (int v : v1)
        {
            dp[a][1][0] += dp[v][0][0];
            nw.push_back(dp[v][0][1] - dp[v][0][0]);
        }
        sort(nw.begin(), nw.end());
        s = 0, mn = 0;
        for (int i = 0; i < nw.size(); i++)
        {
            s += nw[i];
            if (i % 2 == 1) mn = min(mn, s);
        }
        dp[a][1][0] += mn;
        //---
        dp[a][1][1] = 1;
        nw.clear();
        for (int v : v1)
        {
            dp[a][1][1] += dp[v][1][0];
            nw.push_back(dp[v][1][1] - dp[v][1][0]);
        }
        sort(nw.begin(), nw.end());
        s = 0, mn = inf;
        for (int i = 0; i < nw.size(); i++)
        {
            s += nw[i];
            if (i % 2 == 0) mn = min(mn, s);
        }
        dp[a][1][1] += mn;
    }

}

signed main()
{
    ios_base::sync_with_stdio(0);
    cin.tie(nullptr);
    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 >> val[i];
    dfs(1, 1);
    if (dp[1][0][1] >= inf && dp[1][0][0] >= inf)
    {
        cout << "impossible\n";
        return 0;
    }
    cout << min(dp[1][0][1], dp[1][0][0]) << '\n';
}
//

Compilation message

xanadu.cpp: In function 'void dfs(long long int, long long int)':
xanadu.cpp:43:27: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   43 |         for (int i = 0; i < nw.size(); i++)
      |                         ~~^~~~~~~~~~~
xanadu.cpp:59:27: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   59 |         for (int i = 0; i < nw.size(); i++)
      |                         ~~^~~~~~~~~~~
xanadu.cpp:75:27: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   75 |         for (int i = 0; i < nw.size(); i++)
      |                         ~~^~~~~~~~~~~
xanadu.cpp:91:27: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   91 |         for (int i = 0; i < nw.size(); i++)
      |                         ~~^~~~~~~~~~~
xanadu.cpp:109:27: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  109 |         for (int i = 0; i < nw.size(); i++)
      |                         ~~^~~~~~~~~~~
xanadu.cpp:125:27: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  125 |         for (int i = 0; i < nw.size(); i++)
      |                         ~~^~~~~~~~~~~
xanadu.cpp:141:27: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  141 |         for (int i = 0; i < nw.size(); i++)
      |                         ~~^~~~~~~~~~~
xanadu.cpp:157:27: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  157 |         for (int i = 0; i < nw.size(); i++)
      |                         ~~^~~~~~~~~~~

Subtask #1
5.0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 4444 KB Output is correct
2 Correct 2 ms 4444 KB Output is correct
3 Correct 2 ms 4444 KB Output is correct
4 Correct 2 ms 4444 KB Output is correct
5 Correct 2 ms 4440 KB Output is correct

Subtask #2
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 4444 KB Output is correct
2 Correct 2 ms 4444 KB Output is correct
3 Correct 2 ms 4444 KB Output is correct
4 Correct 2 ms 4444 KB Output is correct
5 Correct 2 ms 4440 KB Output is correct
6 Correct 2 ms 4444 KB Output is correct
7 Correct 2 ms 4444 KB Output is correct
8 Correct 1 ms 4444 KB Output is correct
9 Correct 1 ms 4444 KB Output is correct
10 Correct 2 ms 4292 KB Output is correct
11 Correct 2 ms 4444 KB Output is correct
12 Correct 1 ms 4456 KB Output is correct
13 Correct 1 ms 4444 KB Output is correct
14 Correct 1 ms 4444 KB Output is correct
15 Correct 2 ms 4444 KB Output is correct
16 Correct 1 ms 4444 KB Output is correct

Subtask #3
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 46 ms 25264 KB Output is correct
2 Correct 45 ms 25180 KB Output is correct
3 Correct 49 ms 25276 KB Output is correct

Subtask #4
40.0 / 40.0

# Verdict Execution time Memory Grader output
1 Correct 50 ms 25232 KB Output is correct
2 Correct 50 ms 24912 KB Output is correct
3 Correct 47 ms 25428 KB Output is correct
4 Correct 49 ms 10204 KB Output is correct
5 Correct 46 ms 10580 KB Output is correct
6 Correct 41 ms 10576 KB Output is correct
7 Correct 1 ms 4440 KB Output is correct
8 Correct 14 ms 8028 KB Output is correct
9 Correct 47 ms 10636 KB Output is correct
10 Correct 63 ms 10652 KB Output is correct
11 Correct 43 ms 11544 KB Output is correct
12 Correct 52 ms 11612 KB Output is correct
13 Correct 40 ms 10736 KB Output is correct
14 Correct 46 ms 10840 KB Output is correct

Subtask #5
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 4444 KB Output is correct
2 Correct 2 ms 4444 KB Output is correct
3 Correct 2 ms 4444 KB Output is correct
4 Correct 2 ms 4444 KB Output is correct
5 Correct 2 ms 4440 KB Output is correct
6 Correct 2 ms 4444 KB Output is correct
7 Correct 2 ms 4444 KB Output is correct
8 Correct 1 ms 4444 KB Output is correct
9 Correct 1 ms 4444 KB Output is correct
10 Correct 2 ms 4292 KB Output is correct
11 Correct 2 ms 4444 KB Output is correct
12 Correct 1 ms 4456 KB Output is correct
13 Correct 1 ms 4444 KB Output is correct
14 Correct 1 ms 4444 KB Output is correct
15 Correct 2 ms 4444 KB Output is correct
16 Correct 1 ms 4444 KB Output is correct
17 Correct 46 ms 25264 KB Output is correct
18 Correct 45 ms 25180 KB Output is correct
19 Correct 49 ms 25276 KB Output is correct
20 Correct 50 ms 25232 KB Output is correct
21 Correct 50 ms 24912 KB Output is correct
22 Correct 47 ms 25428 KB Output is correct
23 Correct 49 ms 10204 KB Output is correct
24 Correct 46 ms 10580 KB Output is correct
25 Correct 41 ms 10576 KB Output is correct
26 Correct 1 ms 4440 KB Output is correct
27 Correct 14 ms 8028 KB Output is correct
28 Correct 47 ms 10636 KB Output is correct
29 Correct 63 ms 10652 KB Output is correct
30 Correct 43 ms 11544 KB Output is correct
31 Correct 52 ms 11612 KB Output is correct
32 Correct 40 ms 10736 KB Output is correct
33 Correct 46 ms 10840 KB Output is correct
34 Correct 2 ms 4444 KB Output is correct
35 Correct 1 ms 4444 KB Output is correct
36 Correct 2 ms 4444 KB Output is correct
37 Correct 1 ms 4444 KB Output is correct
38 Correct 1 ms 4444 KB Output is correct
39 Correct 2 ms 4440 KB Output is correct
40 Correct 2 ms 4696 KB Output is correct
41 Correct 1 ms 4444 KB Output is correct
42 Correct 1 ms 4444 KB Output is correct
43 Correct 3 ms 4444 KB Output is correct
44 Correct 2 ms 4444 KB Output is correct
45 Correct 49 ms 25180 KB Output is correct
46 Correct 47 ms 25000 KB Output is correct
47 Correct 50 ms 25428 KB Output is correct
48 Correct 37 ms 10072 KB Output is correct
49 Correct 41 ms 10588 KB Output is correct
50 Correct 52 ms 10716 KB Output is correct
51 Correct 2 ms 4440 KB Output is correct
52 Correct 15 ms 8028 KB Output is correct
53 Correct 42 ms 10452 KB Output is correct
54 Correct 41 ms 10328 KB Output is correct
55 Correct 61 ms 11552 KB Output is correct
56 Correct 43 ms 11612 KB Output is correct
57 Correct 40 ms 10572 KB Output is correct
58 Correct 41 ms 10836 KB Output is correct
59 Correct 17 ms 7768 KB Output is correct
60 Correct 36 ms 10080 KB Output is correct
61 Correct 51 ms 10312 KB Output is correct
62 Correct 45 ms 10324 KB Output is correct
63 Correct 43 ms 10320 KB Output is correct
64 Correct 42 ms 10364 KB Output is correct
65 Correct 40 ms 10832 KB Output is correct
66 Correct 39 ms 10708 KB Output is correct
67 Correct 35 ms 12916 KB Output is correct
68 Correct 33 ms 12884 KB Output is correct
69 Correct 34 ms 12884 KB Output is correct
70 Correct 33 ms 12884 KB Output is correct