Submission #376313

#	Time	Username	Problem	Language	Result	Execution time	Memory
376313		YJU	Paprike (COI18_paprike)	C++14	0 / 100	1087 ms	26732 KiB

paprike

#include<bits/stdc++.h>
#pragma GCC optimize("unroll-loops,no-stack-protector,Ofast")
using namespace std;
typedef long long ll;
typedef long double ld;
typedef pair<ll,ll> pll;
const ll N=2e5+5;
const ll INF=(1LL<<60);
const ld pi=acos(-1);
const ll MOD=1e9+7;
#define REP(i,n) for(int i=0;i<n;++i)
#define REP1(i,n) for(int i=1;i<=n;++i)
#define pb push_back
#define mp make_pair
#define X first
#define Y second
#define lwb lower_bound
#define setp setprecision
#define SZ(_a) (ll)_a.size()

ll n,k,w[N],sum[N],x,y,dp[N];
vector<ll> v[N];

void DFS(ll nd,ll pa){
	sum[nd]=w[nd];
	dp[nd]=0;
	vector<ll> lis;
    for(auto i:v[nd]){
		if(i==pa)continue;
		DFS(i,nd);
		dp[nd]+=dp[i];
		lis.pb(sum[i]);
    }
    sort(lis.rbegin(),lis.rend());
    for(ll i:lis){
		if(i+sum[nd]>k)++dp[nd];
		else sum[nd]+=i;
    }
    //return cnt;
}

int main(){
	ios_base::sync_with_stdio(0);cin.tie(0);
    cin>>n>>k;
	REP1(i,n)cin>>w[i];
	REP(i,n-1){
		cin>>x>>y;
		v[x].pb(y);v[y].pb(x);
	}
	ll ans=INF;
	REP1(i,n){
		DFS(i,0);
		ans=min(ans,dp[i]);
	}
	cout<<ans<<"\n";
	return 0;
}

• Subtask 1: 0 / 11
• Subtask 2: 0 / 13
• Subtask 3: 0 / 27
• Subtask 4: 0 / 49