Submission #969401

#	Time	Username	Problem	Language	Result	Execution time	Memory
969401		aeg	Stranded Far From Home (BOI22_island)	C++14	100 / 100	480 ms	58036 KiB

island

#include <bits/stdc++.h>

using namespace std;

const int N = (int)2e5 + 7;
 
int n, m, a[N], p[N];
vector<int> pos[N];
vector<int> need[N];
bool ans[N];
 
set<pair<long long, int> > have;
long long s[N];
 
void comb(int u, int v) {
	int l = p[u];
	int r = p[v];
	if(l == r) {
		return;
	}
	have.erase({s[l], l});
	have.erase({s[r], r});
	if((int)pos[l].size() > (int)pos[r].size()) {
		for(auto x : pos[r]) {
			p[x] = l;
			pos[l].push_back(x);
		}	
	    for(auto x : need[r]) {
	    	need[l].push_back(x);
	    }
		pos[r].clear();
		need[r].clear();        		
		s[l] += s[r];
		if(!need[l].empty()) {
			have.insert({s[l], l});
		}
	} else {
		for(auto x : pos[l]) {
			p[x] = r;
			pos[r].push_back(x);
		}	
		for(auto x : need[l]) {
			need[r].push_back(x);
		}
		pos[l].clear();
		need[l].clear();
		s[r] += s[l];
		if(!need[r].empty()) {
			have.insert({s[r], r});
		}
	}
}
 
long long val[N];
 
int b[N]; 
 
bool cmp2(int i, int j) {
	return a[i] < a[j];
}
 
vector<int> g[N];
 
int main() {	
	cin.tie(0)->sync_with_stdio(0);
	cin >> n >> m;
	for(int i = 1; i <= n; ++i) {
		cin >> a[i];
		p[i] = i;
		b[i] = i;
		s[i] = a[i];
		pos[i].push_back(i);
		need[i].push_back(i);
	}
	for(int i = 1; i <= n; ++i) {
		ans[i] = 1;
	}    
	for(int i = 1; i <= m; ++i) {
		int u, v;
		cin >> u >> v;
		g[u].push_back(v);
		g[v].push_back(u);
	}    
	sort(b+1, b+1+n, cmp2);
	for(int i = 1; i <= n; ++i) {
		if(a[b[i]] == a[b[n]]) {
			break;
		}
		int r = i;
		while(r<n && a[b[r]] == a[b[r+1]]) {
			r++;
		}
		for(int k = i; k <= r; ++k) {
			have.insert({a[b[r]], b[k]});
		}
		for(int k = i; k <= r; ++k) {
			for(auto u : g[b[k]]) {
				if(a[u] <= a[b[k]]) {
					comb(u, b[k]);
				}
			}
		}
		for(int k = i; k <= r; ++k) {
			for(auto u : g[b[k]]) {
				long long cur = s[p[b[k]]];
				if(cur >= a[u]) {
					comb(u, b[k]);
				}
			}
		}
		vector<pair<long long, int> > del;
		for(auto [cur, k] : have) {
			if(cur < a[b[r+1]]) {
				for(auto x : need[k]) {
					ans[x] = 0;
				}
				del.push_back({cur, k});
				need[k].clear();
			} else {
				break;
			}
		}
		for(auto e : del) {
			have.erase(e);
		}
		i = r;
	}
	for(int i = 1; i <= n; ++i) {
		cout << ans[i];
	}
	return 0;
}

Compilation message (stderr)

island.cpp: In function 'int main()':
island.cpp:112:12: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
  112 |   for(auto [cur, k] : have) {
      |            ^

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