Submission #578151

#	Time	Username	Problem	Language	Result	Execution time	Memory
578151		8e7	Stranded Far From Home (BOI22_island)	C++17	100 / 100	983 ms	94796 KiB

island

//Challenge: Accepted
#include <bits/stdc++.h>
#pragma GCC optimize("Ofast")
using namespace std;
#ifdef zisk
void debug(){cout << endl;}
template<class T, class ... U> void debug(T a, U ... b){cout << a << " ", debug(b...); }
template<class T> void pary(T l, T r) {
	while (l != r) cout << *l << " ", l++;
	cout << endl;
}
#else
#define debug(...) 0
#define pary(...) 0
#endif
#define ll long long
#define maxn 200005
#define maxc 31
#define pii pair<int, int>
#define ff first
#define ss second
#define io ios_base::sync_with_stdio(0);cin.tie(0);
const ll inf = 1LL<<30;
vector<int> adj[maxn];
ll sum[maxc][maxn];
int mi[maxc][maxn], comp[maxc][maxn], smi[maxc][maxn];
int idx[maxc][maxn];
int w[maxn];
int lev[maxn];
 
bool vis[maxn], tv[maxn];
void dfs(int n, int id, int l) {
	vis[n] = 1;	
	sum[l][id] += w[n];
	comp[l][n] = id;
	for (int v:adj[n]) {
		if (!vis[v] && lev[v] < l) dfs(v, id, l);
	}
}
int main() {
	io
	int n, m;
	cin >> n >> m;
	ll tot = 0;
	for (int i = 1;i <= n;i++) cin >> w[i], tot += w[i];
	for (int i = 0;i < m;i++) {
		int u, v;
		cin >> u >> v;
		adj[u].push_back(v);
		adj[v].push_back(u);
	}
	for (int i = 1;i <= n;i++) {
		ll tmp = w[i];
		while (tmp >= 2) {
			lev[i]++;
			tmp >>= 1;
		}
	}
	for (int j = 0;j <= n;j++) mi[0][j] = smi[0][j] = inf;
	for (int i = 1;i < maxc;i++) {
		for (int j = 1;j <= n;j++) vis[j] = 0, mi[i][j] = smi[i][j] = inf;
		mi[i][0] = smi[i][0] = inf;
		int cnt = 1;
		for (int j = 1;j <= n;j++) {
			if (!vis[j] && lev[j] < i) {
				dfs(j, cnt, i);
				//debug(i, j, cnt, sum[i][c]);
				cnt++;
			}
		}
		for (int j = 1;j <= n;j++) {
			if (lev[j] >= i) {
				for (int k:adj[j]) {
					if (lev[k] < i) {
						int c = comp[i][k];
						if (w[j] < mi[i][c]) {
							smi[i][c] = mi[i][c];
							mi[i][c] = w[j];
							idx[i][c] = j;
						} else {
							smi[i][c] = min(smi[i][c], (int)w[j]);
						}
					}
				}
			}
		}
	}
	string ans;
	for (int i = 1;i <= n;i++) {
		int cur = lev[i];
		bool poss = 0, fi = 1;
		while (cur < maxc) {
			ll p = 0;
			int val = inf;
			if (fi) {
				fi = 0;
				p = w[i];
				vector<int> v;
				for (int j:adj[i]) {
					if (lev[j] < cur && !tv[comp[cur][j]]) {
						int c = comp[cur][j];
						tv[c] = 1;
						p += sum[cur][c];
						v.push_back(c);
						if (idx[cur][c] == i) val = min(val, smi[cur][c]);
						else val = min(val, mi[cur][c]);
					} else if (lev[j] >= cur) {
						val = min(val, (int)w[j]);
					}
				}
				for (int j:v) tv[j] = 0;
			} else {
				val = min(val, mi[cur][comp[cur][i]]);
			}
			if (comp[cur][i]) p += sum[cur][comp[cur][i]];
			//debug(cur, p, val);
			if (p == tot) {
				poss = 1;
				break;
			} else if (p < val) {
				break;
			} else {
				cur++;
			}
		}
		//debug();
		if (poss) ans += '1';
		else ans += '0';
	}
	cout << ans << "\n";
}
/*
5 4
7 10 1 5 9 
1 2 
3 5 
3 4 
4 1 
*/

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