Submission #896653

#	Time	Username	Problem	Language	Result	Execution time	Memory
896653		borisAngelov	Biochips (IZhO12_biochips)	C++17	60 / 100	152 ms	524288 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 dp[maxn][maxm];
int tmpDP[maxn][maxm];

int subtreeSize[maxn];

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

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

            upTo = m;

            for (int j = 1; j <= m; ++j)
            {
                tmpDP[node][j] = dp[node][j];
            }

            for (int j = 0; j <= upTo; ++j)
            {
                for (int k = 0; k <= upTo - j; ++k)
                {
                    tmpDP[node][j + k] = max(tmpDP[node][j + k], dp[node][j] + dp[tree[node][i]][k]);
                }
            }

            for (int j = 1; j <= m; ++j)
            {
                dp[node][j] = tmpDP[node][j];
            }
        }
    }

    dp[node][1] = max(dp[node][1], a[node]);
}

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;
            tmpDP[i][j] = -inf;
        }
    }

    dfs(root, -1);

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

    return 0;
}

Compilation message (stderr)

biochips.cpp: In function 'void dfs(int, int)':
biochips.cpp:26:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   26 |     for (int i = 0; i < tree[node].size(); ++i)
      |                     ~~^~~~~~~~~~~~~~~~~~~

• Subtask 1: 60 / 100