oj.uz

Submission #604093

# Submission time Handle Problem Language Result Execution time Memory
604093 2022-07-24T17:46:58 Z l_reho Stranded Far From Home (BOI22_island) C++14
10 / 100
 369 ms 31032 KB 
#include<bits/stdc++.h>
using namespace std;

#define ll long long

struct info{
	int node;
	ll people;
	
	bool operator <(const info &i) const{
		return people > i.people;
	}
	
};

int N, M;

vector<ll> A;
vector<pair<ll, int>> A1;
vector<bool> taken, vis;
vector<vector<int>> graph;
vector<ll> P;

void dfs(int curr){
	vis[curr] = true;
	
	vector<int> adj = graph[curr];
	
	P[curr] = A[curr];
	
	for(int a : adj){
		if(vis[a]) continue;
		dfs(a);
		
		P[curr] += P[a];
		
	}
	
	
	// cout<<curr<<" "<<P[curr]<<endl;
}
/*

5 4
40 15 50 30 20
1 2
2 3
3 4
4 5
 
 
*/
void solver(int curr, int p, vector<int> &ans){
	vis[curr] = true;
	vector<int> adj = graph[curr];
	
	if((int)adj.size() == 1 && curr){
		if(P[curr] >= A[p]){
			ans[curr] = 1;
		}else{
			ans[curr] = 0;
		}
		return;
	}
	
	for(int a : adj){
		if(vis[a]) continue;
		
		if(curr){
			if(P[curr] >= A[p]){
				ans[curr] = 1;
			}else{
				ans[curr] = 0;
				continue;
			}
		}
		
		solver(a, curr, ans);
		
	}
	
}

void solve(){
	cin>>N>>M;
	
	A.assign(N, 0);
	A1.assign(N, pair<ll, int>());
	
	P.assign(N, 0);
	
	graph.assign(N, vector<int>());
	vis.assign(N, false);
	
	for(int i = 0; i < N; i++){
		int v;
		cin>>v;
		A[i] = v;
		A1[i] = {v, i};
	}
	
	sort(A1.begin(), A1.end(), greater<pair<ll, int>>());
	
	bool subtask3 = true;
	
	for(int i = 0; i < M; i++){
		int a, b;
		cin>>a>>b;
		a--;
		b--;
		graph[a].push_back(b);
		graph[b].push_back(a);
		
		subtask3 &= abs(a-b) == 1;
	}
	vector<int> ans(N, 2);
	
	
	ll sum = accumulate(A.begin(), A.end(), 0LL);
	
	bool subtask1 = (N <= 2000 && M <= 2000);
	
	if(subtask1){
		int last_color = N;
		
		for(int color = 0; color < last_color; color++){
			if(ans[color] != 2) continue;
			priority_queue<info> pq;
			// inizializzo la pq
			vector<int> adj = graph[color];
			
			taken.assign(N, false);
			taken[color] = true;
			
			for(int a : adj)
				pq.push({a, A[a]});
			
			ll total = A[color];
			stack<int> nodes;
			
			while(!pq.empty()){
				info i = pq.top();
				
				pq.pop();
				
				int node = i.node;
				ll abitants = i.people;
				
				if(taken[node]) continue;
				
				taken[node] = true;
				
				if(abitants > total)
					break;
				
				if(ans[node] == 1){
					total = sum;
					break;
				}
					
				nodes.push(node);
				total += abitants;
				vector<int> adj = graph[node];

				for(int a : adj){
					if(taken[a]) continue;
					pq.push({a, A[a]});
				}
				
			}
			// se ans[color] è false, allora saranno false anche tutti quelli
			// che sono stati convinti durante il processo e quindi è inutile
			// ricalcolarli
			ans[color] = total == sum;
			if(!ans[color]){
				while(!nodes.empty()){
					ans[nodes.top()] = 0;
					nodes.pop();
				}
			}
		}
		
		for(int i = 0; i < N; i++) cout<<ans[i];
		cout<<endl;
		return;
	}

	if(subtask3){
		vector<ll> pref_sum(N+1, 0);
		
		for(int i = 0; i < N; i++){
			pref_sum[i+1] += pref_sum[i] + A[i];
		}
		
		set<int> s;
		ans[A1[0].second] = 1;
		s.insert(A1[0].second);
		for(int i = 1; i < N; i++){
			int color = A1[i].second;
			// mi serve il primo abitante sulla sinistra già preso e 
			// il primo abitante sulla destra già preso cioè ans[i] = true;
			auto r = s.lower_bound(color);
			auto l = r;
			int r_idx = 0;
			int l_idx = 0;
			
			if(l == s.begin()){
				l_idx = -1;
			}else l_idx = *(--l);
			
			if(r == s.end()){
				r_idx = N;
			}else r_idx = *r;
			
			// cout<<"DEBUG-->"<<color<<" "<<l_idx<<" "<<r_idx<<endl;
			ans[color] = (pref_sum[r_idx] - pref_sum[l_idx+1]) >= A1[i-1].first;
			
			if(ans[color])
				s.insert(color);
		}
		
		for(int i = 0; i < N; i++) cout<<ans[i];
		cout<<endl;
		return;
	}

	dfs(0);

	vis.assign(N, false);
	ans.assign(N, false);
	
	ans[0] = 1;
	
	solver(0, -1, ans);
	
	for(int i = 0; i < N; i++) cout<<ans[i];
	cout<<endl;
	
}

int main(){
	solve();
	return 0;
}

Subtask #1
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 212 KB Output is correct
2 Correct 0 ms 212 KB Output is correct
3 Correct 0 ms 212 KB Output is correct
4 Correct 4 ms 468 KB Output is correct
5 Correct 4 ms 468 KB Output is correct
6 Correct 3 ms 472 KB Output is correct
7 Correct 6 ms 468 KB Output is correct
8 Correct 4 ms 340 KB Output is correct
9 Correct 3 ms 468 KB Output is correct
10 Correct 4 ms 468 KB Output is correct
11 Correct 4 ms 468 KB Output is correct
12 Correct 4 ms 468 KB Output is correct
13 Correct 3 ms 468 KB Output is correct
14 Correct 9 ms 468 KB Output is correct

Subtask #2
0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 212 KB Output is correct
2 Correct 0 ms 212 KB Output is correct
3 Correct 285 ms 31032 KB Output is correct
4 Correct 297 ms 28596 KB Output is correct
5 Correct 297 ms 18080 KB Output is correct
6 Correct 369 ms 18544 KB Output is correct
7 Correct 312 ms 18636 KB Output is correct
8 Correct 320 ms 18832 KB Output is correct
9 Correct 271 ms 18592 KB Output is correct
10 Correct 295 ms 20080 KB Output is correct
11 Correct 233 ms 20076 KB Output is correct
12 Correct 288 ms 18704 KB Output is correct
13 Incorrect 268 ms 29372 KB Output isn't correct
14 Halted 0 ms 0 KB -

Subtask #3
0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 212 KB Output is correct
2 Incorrect 365 ms 26284 KB Output isn't correct
3 Halted 0 ms 0 KB -

Subtask #4
0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 212 KB Output is correct
2 Incorrect 344 ms 20764 KB Output isn't correct
3 Halted 0 ms 0 KB -

Subtask #5
0 / 35.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 212 KB Output is correct
2 Correct 0 ms 212 KB Output is correct
3 Correct 0 ms 212 KB Output is correct
4 Correct 4 ms 468 KB Output is correct
5 Correct 4 ms 468 KB Output is correct
6 Correct 3 ms 472 KB Output is correct
7 Correct 6 ms 468 KB Output is correct
8 Correct 4 ms 340 KB Output is correct
9 Correct 3 ms 468 KB Output is correct
10 Correct 4 ms 468 KB Output is correct
11 Correct 4 ms 468 KB Output is correct
12 Correct 4 ms 468 KB Output is correct
13 Correct 3 ms 468 KB Output is correct
14 Correct 9 ms 468 KB Output is correct
15 Correct 0 ms 212 KB Output is correct
16 Correct 0 ms 212 KB Output is correct
17 Correct 285 ms 31032 KB Output is correct
18 Correct 297 ms 28596 KB Output is correct
19 Correct 297 ms 18080 KB Output is correct
20 Correct 369 ms 18544 KB Output is correct
21 Correct 312 ms 18636 KB Output is correct
22 Correct 320 ms 18832 KB Output is correct
23 Correct 271 ms 18592 KB Output is correct
24 Correct 295 ms 20080 KB Output is correct
25 Correct 233 ms 20076 KB Output is correct
26 Correct 288 ms 18704 KB Output is correct
27 Incorrect 268 ms 29372 KB Output isn't correct
28 Halted 0 ms 0 KB -