Submission #463939

#	Time	Username	Problem	Language	Result	Execution time	Memory
463939		blue	Cat in a tree (BOI17_catinatree)	C++17	100 / 100	179 ms	92612 KiB

catinatree

#include <iostream>
#include <deque>
#include <vector>
using namespace std;
const int maxN = 200'000;
int N, D, x, res = 0;
vector<int> children[maxN];
deque<int> dfs(int u)
{
    deque<int> res(1, 1);
    for(int v: children[u])
    {
        deque<int> add = dfs(v);
        add.push_front(add.front());
        if(res.size() < add.size()) swap(res, add);
        for(int i = 0; i < add.size(); i++)
        {
            int opt1 = add[i] + (D-i < res.size() ? res[max(D-i, i)] : 0);
            int opt2 = res[i] + (D-i < add.size() ? add[max(D-i, i)] : 0);
            res[i] = max(res[i], max(opt1, opt2));
        }
        for(int i = add.size(); i >= 0; i--)
            if(i+1 < res.size())
                res[i] = max(res[i], res[i+1]);
    }
    return res;
}
int main()
{
    cin >> N >> D;
    for(int i = 1; i < N; i++)
    {
        cin >> x;
        children[x].push_back(i);
    }
    for(int r: dfs(0)) res = max(res, r);
    cout << res << '\n';
}

Compilation message (stderr)

catinatree.cpp: In function 'std::deque<int> dfs(int)':
catinatree.cpp:16:26: warning: comparison of integer expressions of different signedness: 'int' and 'std::deque<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   16 |         for(int i = 0; i < add.size(); i++)
      |                        ~~^~~~~~~~~~~~
catinatree.cpp:18:38: warning: comparison of integer expressions of different signedness: 'int' and 'std::deque<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   18 |             int opt1 = add[i] + (D-i < res.size() ? res[max(D-i, i)] : 0);
      |                                  ~~~~^~~~~~~~~~~~
catinatree.cpp:19:38: warning: comparison of integer expressions of different signedness: 'int' and 'std::deque<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   19 |             int opt2 = res[i] + (D-i < add.size() ? add[max(D-i, i)] : 0);
      |                                  ~~~~^~~~~~~~~~~~
catinatree.cpp:23:20: warning: comparison of integer expressions of different signedness: 'int' and 'std::deque<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   23 |             if(i+1 < res.size())
      |                ~~~~^~~~~~~~~~~~

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