Submission #925056

#	Time	Username	Problem	Language	Result	Execution time	Memory
925056		12345678	Cat in a tree (BOI17_catinatree)	C++17	100 / 100	292 ms	250500 KiB

catinatree

#include <bits/stdc++.h>

using namespace std;

const int nx=2e5+5;
int n, x, k;
deque<int> dq[nx];
vector<int> d[nx];

void dfs(int u, int p)
{
    dq[u].push_back(1);
    for (auto v:d[u])
    {
        if (v==p) continue;
        dfs(v, u);
        dq[v].push_front(dq[v].front());
        if (dq[v].size()>dq[u].size()) swap(dq[u], dq[v]);
        for (int i=0; i<dq[v].size(); i++)
        {
            int vu=dq[u][i]+((k-i<dq[v].size())?dq[v][max(i, k-i)]:0);
            int vv=dq[v][i]+((k-i<dq[u].size())?dq[u][max(i, k-i)]:0);
            dq[u][i]=max({dq[u][i], vu, vv});
        }
        for (int i=dq[v].size()-2; i>=0; i--) dq[u][i]=max(dq[u][i], dq[u][i+1]);
    }
}

int main()
{
    cin.tie(NULL)->sync_with_stdio(false);
    cin>>n>>k;
    for (int i=1; i<n; i++) cin>>x, d[i].push_back(x), d[x].push_back(i);
    dfs(0, 0);
    cout<<dq[0].front();
}

Compilation message (stderr)

catinatree.cpp: In function 'void dfs(int, int)':
catinatree.cpp:19:24: warning: comparison of integer expressions of different signedness: 'int' and 'std::deque<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   19 |         for (int i=0; i<dq[v].size(); i++)
      |                       ~^~~~~~~~~~~~~
catinatree.cpp:21:34: warning: comparison of integer expressions of different signedness: 'int' and 'std::deque<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   21 |             int vu=dq[u][i]+((k-i<dq[v].size())?dq[v][max(i, k-i)]:0);
      |                               ~~~^~~~~~~~~~~~~
catinatree.cpp:22:34: warning: comparison of integer expressions of different signedness: 'int' and 'std::deque<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   22 |             int vv=dq[v][i]+((k-i<dq[u].size())?dq[u][max(i, k-i)]:0);
      |                               ~~~^~~~~~~~~~~~~

• Subtask 1: 11 / 11
• Subtask 2: 40 / 40
• Subtask 3: 49 / 49