Submission #593600

#	Time	Username	Problem	Language	Result	Execution time	Memory
593600		Blagojce	Stranded Far From Home (BOI22_island)	C++11	10 / 100	1061 ms	408660 KiB

island

#include <bits/stdc++.h>
#define fr(i, n, m) for(int i = (n); i < (m); i ++)
#define st first
#define nd second
#define pb push_back
#define pq priority_queue
#define all(x) begin(x), end(x)

using namespace std;
typedef long long ll;
typedef long double ld;
typedef pair<int,int> pii;


const int mxn = 2e5 + 5;

int n, m;
vector<int> g[mxn];
ll a[mxn];

vector<int> S[mxn];
vector<int> G[mxn];



ll sum[mxn];

int v_count = 0;
int vis_ver[mxn];
int vis_edg[mxn];

vector<int> merge(int u, int v){
	vector<int> cand;
	for(auto vp : S[v]){
		if(vis_ver[vp] == v_count) continue;
		
		S[u].pb(vp);
		sum[u] += a[vp];
		vis_ver[vp] = v_count;
	}
	for(auto ep : G[v]){
		if(vis_edg[ep] == v_count || vis_ver[ep] == v_count) continue;
		G[u].pb(ep);
		cand.pb(ep);
		vis_edg[ep] = v_count;
	}
	return cand;
}

void expand(int u){
	++v_count;
	for(auto e : S[u]) vis_ver[e] = v_count;
	for(auto e : G[u]) vis_edg[e] = v_count;
	
	pq <pair<int,int> > Q;
	for(auto e : G[u]) Q.push({-a[e], e});
	
	while(!Q.empty()){
		int c = Q.top().nd;
		Q.pop();
		if(vis_ver[c] == v_count) continue;
		if(sum[u] < a[c]) continue;
		vector<int> cand = merge(u, c);
		for(auto c : cand){
			Q.push({-a[c], c});
		}
	}
}

int main(){
	cin >> n >> m;
	fr(i, 0, n){
		cin >> a[i];
	}
	fr(i, 0, m){
		int u, v;
		cin >> u >> v;
		--u, --v;
		g[u].pb(v);
		g[v].pb(u);
	}
	fr(i, 0, n){
		G[i] = g[i];
		S[i] = {i};
		sum[i] = a[i];
	}
	fr(i, 0, n){
		expand(i);
	}
	fr(i, 0, n){
		if(S[i].size() > n) cout<<2/0<<endl;
		if((int)S[i].size() == n) cout<<1;
		else cout<<0;
	}
	
}

Compilation message (stderr)

island.cpp: In function 'int main()':
island.cpp:91:18: warning: comparison of integer expressions of different signedness: 'std::vector<int>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   91 |   if(S[i].size() > n) cout<<2/0<<endl;
      |      ~~~~~~~~~~~~^~~
island.cpp:91:30: warning: division by zero [-Wdiv-by-zero]
   91 |   if(S[i].size() > n) cout<<2/0<<endl;
      |                             ~^~

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