Submission #563601

#	Time	Username	Problem	Language	Result	Execution time	Memory
563601		Devigo	Paprike (COI18_paprike)	C++14	0 / 100	71 ms	7364 KiB

paprike

#include <bits/stdc++.h>
using namespace std;

#define pb push_back
#define mp make_pair

const int siz = 1e5+1;
const int mod = 0;

struct node {
	long long u, v;
};


vector<node> el;
vector<long long> par;
vector<long long> rnk;
vector<long long> value;
long long cuts = 0;
long long n, k; 

long long get(long long a) {
	return par[a] = (par[a] == a) ? a : get(par[a]);
}

void join(long long a, long long b) {
	a = get(a); b = get(b);
	if(a != b) {
		if(rnk[a] == rnk[b]) rnk[a]++;
		if(rnk[b] > rnk[a]) swap(a,b);
		par[b] = a; value[a] += value[b];
	}
}

bool good(long long a, long long b) {
	a = get(a); b = get(b);
	return value[a] + value[b] <= k;
}

void mincuts() {
	for(int i=0; i<n-1; i++) {
		long long x = el[i].u; long long y = el[i].v;
		if(good(x,y)) {
			join(x,y);
		}
	}
	set<long long> s;
	for(int i=1; i<=n; i++) {
		long long x = get(i);
		s.insert(x);
	}
	cuts = s.size()-1;
}

bool cmp(node a, node b) {
	long long x = value[a.u] + value[a.v];
	long long y = value[b.u] + value[b.v];
	return x < y;
}

int main() {
	ios::sync_with_stdio(0);
	cin.tie(0);
	cin >> n >> k;
	value.resize(n+1); par.resize(n+1); rnk.resize(n+1);
	for(int i=1; i<=n; i++) {
		int x;
		cin >> x;
		value[i] = x;
	}
	for(int i=1; i<=n; i++) {
		par[i] = i;
	}
	long long m = n-1;
	for(int i=1; i<=m; i++) {
		long long a, b;
		cin >> a >> b;
		el.pb({a,b});
	}
	sort(el.begin(), el.end(), cmp);	
	mincuts();
	cout << cuts << "\n";
	return 0;
}

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