Submission #463940

#	Time	Username	Problem	Language	Result	Execution time	Memory
463940		blue	Cat in a tree (BOI17_catinatree)	C++17	100 / 100	185 ms	92704 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++) res[i] = max(res[i], max(add[i] + (D-i < res.size() ? res[max(D-i, i)] : 0), res[i] + (D-i < add.size() ? add[max(D-i, i)] : 0)));
        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:15:26: warning: comparison of integer expressions of different signedness: 'int' and 'std::deque<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   15 |         for(int i = 0; i < add.size(); i++) res[i] = max(res[i], max(add[i] + (D-i < res.size() ? res[max(D-i, i)] : 0), res[i] + (D-i < add.size() ? add[max(D-i, i)] : 0)));
      |                        ~~^~~~~~~~~~~~
catinatree.cpp:15:84: warning: comparison of integer expressions of different signedness: 'int' and 'std::deque<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   15 |         for(int i = 0; i < add.size(); i++) res[i] = max(res[i], max(add[i] + (D-i < res.size() ? res[max(D-i, i)] : 0), res[i] + (D-i < add.size() ? add[max(D-i, i)] : 0)));
      |                                                                                ~~~~^~~~~~~~~~~~
catinatree.cpp:15:136: warning: comparison of integer expressions of different signedness: 'int' and 'std::deque<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   15 |         for(int i = 0; i < add.size(); i++) res[i] = max(res[i], max(add[i] + (D-i < res.size() ? res[max(D-i, i)] : 0), res[i] + (D-i < add.size() ? add[max(D-i, i)] : 0)));
      |                                                                                                                                    ~~~~^~~~~~~~~~~~
catinatree.cpp:16:53: 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 = add.size(); i >= 0; i--) if(i+1 < res.size()) res[i] = max(res[i], res[i+1]);
      |                                                 ~~~~^~~~~~~~~~~~

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