Submission #711148

#	Time	Username	Problem	Language	Result	Execution time	Memory
711148		YeoBL	Stranded Far From Home (BOI22_island)	C++14	40 / 100	1067 ms	34404 KiB

island

#include <bits/stdc++.h>
using namespace std;
#pragma GCC target("avx2")
#pragma GCC optimize("O3")
#pragma GCC optimize ("unroll-loops")
#define int long long
#define fi first
#define se second
#define mp make_pair
#define pb emplace_back
const int MAX_N = 2e5 + 5;
bool active[MAX_N], ans[MAX_N];
int siz[MAX_N], par[MAX_N], s[MAX_N], powe[MAX_N], requ[MAX_N];
void init(int x){
	for (int i = 0; i < x; i++){
		par[i] = i;
		siz[i] = s[i];
	}
}
int head(int x){
	if (par[x] == x) return x;
	return par[x] = head(par[x]);
}
void merge(int a, int b){
	int pa = head(a), pb = head(b);
	if (pa == pb) return;
	par[pa] = pb;
	siz[pb] += siz[pa];
}
int stronk(int a){
	return siz[head(a)];
}
int32_t main(){
	ios::sync_with_stdio(false);
	cin.tie(0); cout.tie(0);
	int n, m, x, y; cin >> n >> m; 
	fill(requ, requ + n, 1e9);
	vector <int> edg[n];
	for (int i = 0; i < n; i++) cin >> s[i];
	pair <int, int> p[n];
	for (int i = 0; i < n; i++){
		p[i].fi = s[i]; p[i].se = i;
	}
	sort(p, p + n);
	for (int i = 0; i < m; i++){
		cin >> x >> y;
		x -= 1; y -= 1;
		edg[x].pb(y); edg[y].pb(x);
	}
	vector <vector <int> > v;
	for (int i = 0; i < n; i++){
		vector <int> nx;
		nx.pb(p[i].se);
		while (i != n - 1){
			if (p[i + 1].fi == p[i].fi){
				nx.pb(p[i + 1].se);
			}
			else break;
			i += 1;
		}
		v.pb(nx);
	}
	init(n);
	for (auto tmp : v){
		for (auto nd : tmp){
			active[nd] = 1;
			for (auto nx : edg[nd]){
				if (active[nx]) merge(nx, nd);
			}
		}
		for (auto nd : tmp){
			powe[nd] = stronk(nd);
		}
	}
	for (auto nd : v.back()){
		ans[nd] = 1;
	}
	for (int i = n - 1; i >= 0; i--){
		int cur = p[i].se;
		if (requ[cur] <= powe[cur]) ans[cur] = 1;
		if (!ans[cur]) continue;
		queue <int> q;
		q.push(cur);
		vector <int> x;
		while (!q.empty()){
			int curnd = q.front();
			q.pop();
			for (auto nx : edg[curnd]){
				//if (cur == 1) cerr << powe[nx] << ' ' << 
				if (s[nx] <= s[cur] and requ[nx] > s[cur] ){
					requ[nx] = min(s[cur], requ[nx]);
					q.push(nx);
				}
			}
		}
	}
	for (int i = 0; i < n; i++) cout << ans[i];
}

• Subtask 1: 10 / 10
• Subtask 2: 0 / 10
• Subtask 3: 0 / 15
• Subtask 4: 30 / 30
• Subtask 5: 0 / 35