Submission #232943

#	Time	Username	Problem	Language	Result	Execution time	Memory
232943		amoo_safar	Paprike (COI18_paprike)	C++14	100 / 100	83 ms	17144 KiB

paprike

#include <bits/stdc++.h>

#define pb push_back
#define F first
#define S second
#define all(x) x.begin(), x.end()
#define debug(x) cerr << #x << " : " << x << '\n'

using namespace std;

typedef long long ll;
typedef long double ld;
typedef string str;
typedef pair<ll, ll> pll;

const ll Mod = 1000000007LL;
const int N = 1e5 + 10;
const ll Inf = 2242545357980376863LL;
const ll Log = 30;

ll n, k;
ll a[N], dp[N], c[N];
vector<ll> G[N];

bool CMP(int i, int j){
	return c[i] < c[j];
}

void DFS(int u, int p){
	dp[u] = 0;
	c[u] = a[u];
	for(auto adj : G[u]){
		if(adj == p) continue;
		DFS(adj, u);
		dp[u] += dp[adj] + 1;
	}
	sort(all(G[u]), CMP);
	for(auto adj : G[u]){
		if(adj == p) continue;
		if(c[u] + c[adj] <= k){
			dp[u] --;
			c[u] += c[adj];
		}
	}
}

int main(){
	ios::sync_with_stdio(0); cin.tie(0); cout.tie(0);
	cin >> n >> k;
	for(int i = 1; i <= n; i++) cin >> a[i];
	int u, v;
	for(int i = 1; i < n; i++){
		cin >> u >> v;
		G[u].pb(v);
		G[v].pb(u);
	}
	DFS(1, -1);
	cout << dp[1] << '\n';
	return 0;
}

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