Submission #556269

#	Time	Username	Problem	Language	Result	Execution time	Memory
556269		new_acc	Cat in a tree (BOI17_catinatree)	C++14	0 / 100	3 ms	4948 KiB

catinatree

#include<bits/stdc++.h>
#define fi first
#define se second
#define pitem item*
using namespace std;
typedef long long ll;
typedef unsigned long long ull;
typedef vector<int> vi;
typedef vector<ll> vl;
const int N=2e5+10;
const int SS=1<<19;
const int INFi=2e9;
const ll INFl=1e13;
const ll mod2=998244353;
const ll mod=1e9+7;
const ll mod3=1000696969;
const ll p=70032301;
const ull p2=913;
const int L=20;
vi graf[N];
pair<int,int> dp[N];
int n,k;
void dfs(int v,int o){
    vector<pair<int,int> >curr;
    int aktsum=0;
    for(auto u:graf[v]){
        if(u==o) continue;
        dfs(u,v);
        curr.push_back({dp[u].se,dp[u].fi});
        aktsum+=dp[u].fi;
    }
    if(graf[v].size()==1 and v!=o){
        dp[v]={1,0};
        return;
    }
    sort(curr.begin(),curr.end());
    dp[v].fi=0;
    int g=curr.size()-1;
    for(int i=0;i<curr.size()-1;i++){
        if(curr[i].fi+curr[i+1].fi+2>=k){
            g=i;
            break;
        }
    }
    dp[v].fi=aktsum-g,dp[v].se=curr[g].se+1;
    for(auto u:graf[v]){
        if(u==o) continue;
        if(dp[u].se!=k-1) aktsum--;
    }
    aktsum++;
    if(aktsum>dp[v].fi) dp[v]={aktsum,0};
}
void solve(){
    cin>>n>>k;
    for(int a,i=2;i<=n;i++){
        cin>>a;
        a++;
        graf[i].push_back(a),graf[a].push_back(i);
    }
    if(n==1){
        cout<<1<<"\n";
        return;
    }
    dfs(1,1);
    cout<<dp[1].fi<<"\n";
}
int main(){
    ios_base::sync_with_stdio(0),cin.tie(0);
    solve();
}

Compilation message (stderr)

catinatree.cpp: In function 'void dfs(int, int)':
catinatree.cpp:39:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   39 |     for(int i=0;i<curr.size()-1;i++){
      |                 ~^~~~~~~~~~~~~~

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