Submission #896639

#	Time	Username	Problem	Language	Result	Execution time	Memory
896639		borisAngelov	Biochips (IZhO12_biochips)	C++17	0 / 100	2094 ms	415876 KiB

biochips

#include <bits/stdc++.h>

using namespace std;

const int maxn = 200005;
const int maxm = 505;
const int inf = 1e9;

int n, m;

int a[maxn];

int root = -1;
vector<int> tree[maxn];

int subtreeSize[maxn];
int dp[maxn][maxm];

vector<int> childs[maxn];

void dfs(int node, int par)
{
    subtreeSize[node] = 1;

    for (int i = 0; i < tree[node].size(); ++i)
    {
        if (tree[node][i] != par)
        {
            childs[node].push_back(tree[node][i]);
            dfs(tree[node][i], node);
            subtreeSize[node] += subtreeSize[tree[node][i]];
        }
    }

    if (subtreeSize[node] != 1)
    {
        for (int i = 0; i < childs[node].size(); ++i)
        {
            for (int j = m; j >= 1; --j)
            {
                for (int k = m; k >= j; --k)
                {
                    if (dp[node][k - j] == -inf || dp[childs[node][i]][j] == -inf)
                    {
                        continue;
                    }

                    //cout << node << " " << k << " " << j << " " << childs[node][i] << " " << dp[node][k - j] << " " << dp[childs[node][i]][j] << endl;

                    dp[node][k] = max(dp[node][k], dp[node][k - j] + dp[childs[node][i]][j]);
                }
            }
        }
    }
    else
    {
        dp[node][1] = a[node];
    }

    /*cout << node << endl;

    for (int i = 1; i <= m; ++i)
    {
        cout << i << " :: " << dp[node][i] << endl;
    }

    cout << "----------------------------------------------" << endl;*/
}

void fastIO()
{
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
}

int main()
{
    fastIO();

    cin >> n >> m;

    for (int i = 1; i <= n; ++i)
    {
        int par;
        cin >> par >> a[i];

        if (par == 0)
        {
            root = i;
        }
        else
        {
            tree[par].push_back(i);
            tree[i].push_back(par);
        }
    }

    for (int i = 1; i <= n; ++i)
    {
        for (int j = 1; j <= m; ++j)
        {
            dp[i][j] = -inf;
        }
    }

    if (m == 1)
    {
        int ans = 0;

        for (int i = 1; i <= n; ++i)
        {
            ans = max(ans, a[i]);
        }

        cout << ans << endl;

        return 0;
    }

    dfs(root, -1);

    cout << dp[root][m] << endl;

    return 0;
}

Compilation message (stderr)

biochips.cpp: In function 'void dfs(int, int)':
biochips.cpp:25:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   25 |     for (int i = 0; i < tree[node].size(); ++i)
      |                     ~~^~~~~~~~~~~~~~~~~~~
biochips.cpp:37:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   37 |         for (int i = 0; i < childs[node].size(); ++i)
      |                         ~~^~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 0 / 100