Submission #588520

#	Time	Username	Problem	Language	Result	Execution time	Memory
588520		Huy	Cat in a tree (BOI17_catinatree)	C++17	51 / 100	310 ms	524288 KiB

catinatree

/// no sound please
#include<bits/stdc++.h>
#define int long long
#define pii pair<int,int>
#define pic pair<int,char>
#define fi first
#define se second
/*#pragma GCC target ("avx2")
#pragma GCC optimization ("O3")
#pragma GCC optimization ("unroll-loops")
#pragma GCC optimize("Ofast")
#pragma GCC target("avx,avx2,fma")*/
using namespace std;
using ll = long long;
using ull = unsigned long long;
using ldb = long double;
const ll N = (int)1e9 + 1;
const int maxN = (int)3e5 + 5;
const int mod = 1e9 + 7;
//const int mod = 998244353;
const ll infty = 1e18 + 7;
const int base = (int)4e5;

void InputFile()
{
    //freopen("IELTS.inp","r",stdin);
    //freopen("IELTS.out","w",stdout);
    //freopen("test.out","r",stdin);
}

void FastInput()
{
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);
}

int n,d;
vector<vector<int>> adj;

void Read()
{
    cin >> n >> d;
    d = min(d,n);
    adj.resize(n);
    for(int i = 1;i < n;i++)
    {
        int p;
        cin >> p;
        adj[p].push_back(i);
        adj[i].push_back(p);
    }
}

vector<int> dp[maxN];

vector<int> operator+(vector<int> a,vector<int> b)
{
    vector<int> res;
    int sz = min((int)max(a.size(),b.size()+1),d + 1);
    res.resize(sz,0);
    res[0] = a[0];
    for(int i = 1;i < sz;i++)
    {
        if(i - 1 < b.size()) res[i] = max(res[i],b[i-1]);
        if(i < a.size()) res[i] = max(res[i],a[i]);
    }
    for(int i = 0;i < a.size();i++)
    {
        for(int j = 0;j < b.size();j++)
        {
            if(i + j + 1 >= d)
            {
                res[min(i,j+1)] = max(res[min(i,j+1)],a[i] + b[j]);
            }
        }
    }
    return res;
}

void DFS(int u,int p)
{
    dp[u] = {1};
    for(int v : adj[u])
    {
        if(v == p) continue;
        DFS(v,u);
        dp[u] = dp[u] + dp[v];
    }
}

void Solve()
{
    DFS(0,0);

    int res = 0;
    for(int i = 0;i < n;i++)
    {
        for(int j = 0;j < dp[i].size();j++)
        {
            res = max(res,dp[i][j]);
        }
    }
    cout << res;
}

void Debug()
{

}


int32_t main()
{
    FastInput();
    //InputFile();
    //int sub_type;
    //cin >> sub_type;
    //Sieve();
    //Prepare();
    int test;
    //cin >> test;
    test = 1;
    while(test--)
        //for(int prc = 1; prc <= test; prc++)
    {
        Read();
        Solve();
        //Debug();
    }
}

Compilation message (stderr)

catinatree.cpp: In function 'std::vector<long long int> operator+(std::vector<long long int>, std::vector<long long int>)':
catinatree.cpp:64:18: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   64 |         if(i - 1 < b.size()) res[i] = max(res[i],b[i-1]);
      |            ~~~~~~^~~~~~~~~~
catinatree.cpp:65:14: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   65 |         if(i < a.size()) res[i] = max(res[i],a[i]);
      |            ~~^~~~~~~~~~
catinatree.cpp:67:21: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   67 |     for(int i = 0;i < a.size();i++)
      |                   ~~^~~~~~~~~~
catinatree.cpp:69:25: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   69 |         for(int j = 0;j < b.size();j++)
      |                       ~~^~~~~~~~~~
catinatree.cpp: In function 'void Solve()':
catinatree.cpp:98:25: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   98 |         for(int j = 0;j < dp[i].size();j++)
      |                       ~~^~~~~~~~~~~~~~

• Subtask 1: 11 / 11
• Subtask 2: 40 / 40
• Subtask 3: 0 / 49