oj.uz

Submission #923785

# Submission time Handle Problem Language Result Execution time Memory
923785 2024-02-07T18:47:02 Z vjudge1 The Xana coup (BOI21_xanadu) C++17
100 / 100
 65 ms 26716 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 2 ms 4444 KB Output is correct
2 Correct 1 ms 4440 KB Output is correct
3 Correct 1 ms 4444 KB Output is correct
4 Correct 1 ms 4444 KB Output is correct
5 Correct 1 ms 4444 KB Output is correct

Subtask #2
15.0 / 15.0

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

Subtask #3
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 52 ms 26712 KB Output is correct
2 Correct 46 ms 26436 KB Output is correct
3 Correct 48 ms 26712 KB Output is correct

Subtask #4
40.0 / 40.0

# Verdict Execution time Memory Grader output
1 Correct 46 ms 26572 KB Output is correct
2 Correct 50 ms 26316 KB Output is correct
3 Correct 48 ms 26716 KB Output is correct
4 Correct 37 ms 11348 KB Output is correct
5 Correct 41 ms 11868 KB Output is correct
6 Correct 42 ms 12056 KB Output is correct
7 Correct 2 ms 4444 KB Output is correct
8 Correct 15 ms 8436 KB Output is correct
9 Correct 44 ms 11612 KB Output is correct
10 Correct 42 ms 11868 KB Output is correct
11 Correct 44 ms 12636 KB Output is correct
12 Correct 52 ms 13100 KB Output is correct
13 Correct 38 ms 11860 KB Output is correct
14 Correct 48 ms 12272 KB Output is correct

Subtask #5
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 4444 KB Output is correct
2 Correct 1 ms 4440 KB Output is correct
3 Correct 1 ms 4444 KB Output is correct
4 Correct 1 ms 4444 KB Output is correct
5 Correct 1 ms 4444 KB Output is correct
6 Correct 2 ms 4440 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 4444 KB Output is correct
11 Correct 1 ms 4444 KB Output is correct
12 Correct 1 ms 4444 KB Output is correct
13 Correct 2 ms 4444 KB Output is correct
14 Correct 2 ms 4440 KB Output is correct
15 Correct 2 ms 4444 KB Output is correct
16 Correct 2 ms 4444 KB Output is correct
17 Correct 52 ms 26712 KB Output is correct
18 Correct 46 ms 26436 KB Output is correct
19 Correct 48 ms 26712 KB Output is correct
20 Correct 46 ms 26572 KB Output is correct
21 Correct 50 ms 26316 KB Output is correct
22 Correct 48 ms 26716 KB Output is correct
23 Correct 37 ms 11348 KB Output is correct
24 Correct 41 ms 11868 KB Output is correct
25 Correct 42 ms 12056 KB Output is correct
26 Correct 2 ms 4444 KB Output is correct
27 Correct 15 ms 8436 KB Output is correct
28 Correct 44 ms 11612 KB Output is correct
29 Correct 42 ms 11868 KB Output is correct
30 Correct 44 ms 12636 KB Output is correct
31 Correct 52 ms 13100 KB Output is correct
32 Correct 38 ms 11860 KB Output is correct
33 Correct 48 ms 12272 KB Output is correct
34 Correct 1 ms 4444 KB Output is correct
35 Correct 1 ms 4444 KB Output is correct
36 Correct 1 ms 4440 KB Output is correct
37 Correct 2 ms 4444 KB Output is correct
38 Correct 1 ms 4444 KB Output is correct
39 Correct 2 ms 4444 KB Output is correct
40 Correct 2 ms 4444 KB Output is correct
41 Correct 2 ms 4444 KB Output is correct
42 Correct 1 ms 4444 KB Output is correct
43 Correct 2 ms 4440 KB Output is correct
44 Correct 1 ms 4440 KB Output is correct
45 Correct 46 ms 26564 KB Output is correct
46 Correct 54 ms 26420 KB Output is correct
47 Correct 49 ms 26708 KB Output is correct
48 Correct 39 ms 11356 KB Output is correct
49 Correct 42 ms 11860 KB Output is correct
50 Correct 42 ms 11868 KB Output is correct
51 Correct 2 ms 4444 KB Output is correct
52 Correct 15 ms 8288 KB Output is correct
53 Correct 41 ms 11768 KB Output is correct
54 Correct 58 ms 12016 KB Output is correct
55 Correct 59 ms 12760 KB Output is correct
56 Correct 65 ms 12884 KB Output is correct
57 Correct 40 ms 11904 KB Output is correct
58 Correct 51 ms 12208 KB Output is correct
59 Correct 15 ms 8280 KB Output is correct
60 Correct 37 ms 11280 KB Output is correct
61 Correct 45 ms 11660 KB Output is correct
62 Correct 46 ms 11828 KB Output is correct
63 Correct 42 ms 11612 KB Output is correct
64 Correct 42 ms 11676 KB Output is correct
65 Correct 49 ms 12108 KB Output is correct
66 Correct 38 ms 12112 KB Output is correct
67 Correct 43 ms 14152 KB Output is correct
68 Correct 34 ms 14136 KB Output is correct
69 Correct 35 ms 14132 KB Output is correct
70 Correct 35 ms 14140 KB Output is correct