Submission #851064

#	Time	Username	Problem	Language	Result	Execution time	Memory
851064		thefless	Cat in a tree (BOI17_catinatree)	C++14	11 / 100	1053 ms	9564 KiB

catinatree

#include <bits/stdc++.h>
#define ll long long
#define task "name"
#define pii pair<ll , int>
#define se second
#define fi first
#define pb push_back
#define BIT(s , i) (((s) >> (i)) & 1)
#define MASK(i) (1LL << (i))
using namespace std;

const int N = 2e3 + 5;
const int MOD = 1e9 + 7;
const ll loo = 1e18;
template<typename T1 , typename T2> bool maximize(T1 &a , T2 b){if(a < b){a = b; return 1;}return 0;}
template<typename T1 , typename T2> bool minimize(T1 &a , T2 b){if(a > b){a = b; return 1;}return 0;}

int n;
int d;
vector<int> adj[N];

struct SUB2{
    int dp[1505][1505];
    int cnt[1505];
    void combine(int u , int v){
        memset(cnt , 0 , sizeof (int) * (n + 1));
        for(int i = 0 ; i <= n ; i++){
            for(int j = 0 ; j < n ; j++){
                if(i + j + 1 < d) maximize(cnt[min(i , j + 1)] , max(dp[u][i] , dp[v][j]));
                else maximize(cnt[min(i , j + 1)] , dp[u][i] + dp[v][j]);
            }
        }
        for(int i = 0 ; i <= n ; i++) dp[u][i] = cnt[i];
    }
    void dfs(int u , int par){
        dp[u][0] = 1;
        for(auto v : adj[u]){
            if(v == par) continue;
            dfs(v , u);
            combine(u , v);
        }
    }
}f;
void sub2(){
    f.dfs(0 , -1);
    cout << *max_element(f.dp[0] , f.dp[0] + n + 1);
}
void solve(){
    cin >> n >> d;
    for(int i = 1 ; i < n ; i++){
        int u;
        cin >> u;
        adj[u].pb(i);
        adj[i].pb(u);
    }
    if(d >= n) return void(cout << 1);
    sub2();
}

int main(){
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    if(fopen(task".inp" , "r")){
        freopen(task".inp" , "r" , stdin);
        freopen(task".out" , "w" , stdout);
    }
    solve();
}

Compilation message (stderr)

catinatree.cpp: In function 'int main()':
catinatree.cpp:64:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   64 |         freopen(task".inp" , "r" , stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~
catinatree.cpp:65:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   65 |         freopen(task".out" , "w" , stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~

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