Submission #604190

#	Time	Username	Problem	Language	Result	Execution time	Memory
604190		DanerZein	Stranded Far From Home (BOI22_island)	C++14	0 / 100	265 ms	16204 KiB

island

#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef vector<int> vi;
typedef pair<int,int> ii;
const int MAX_N=2e5+10;
vector<vi> G;
int ha[MAX_N];
bool vis[MAX_N];
int n,m;
void bfs(int u){
  for(int i=0;i<n;i++) vis[i]=0;
  priority_queue<ii, vector<ii>, greater<ii> > q;
  vis[u]=1; 
  ll co=ha[u];
  for(auto &v:G[u]){
    q.push(ii(ha[v],v));
  }
  while(!q.empty()){
    int x=q.top().second; q.pop();
    if(co<ha[x]) continue;
    vis[x]=1;
    co+=ha[x];
    for(auto &v:G[x]){
      if(!vis[v]){
        q.push(ii(ha[v],v));
      }
    }
  }
}
int pa[MAX_N];
ll sb[MAX_N];
void dfs(int u,int p){
  pa[u]=p;
  sb[u]=ha[u];
  for(auto &v:G[u]){
    if(v!=p){
      dfs(v,u);
      sb[u]+=sb[v];
    }
  }
}
ll sum[MAX_N];
bool habitant(int a,int b){
  return ha[a]>ha[b];
}
int main(){
  cin>>n>>m;
  G.resize(n+1);
  for(int i=0;i<n;i++) cin>>ha[i];
  for(int i=0;i<m;i++){
    int a,b; cin>>a>>b;
    a--; b--;
    G[a].push_back(b);
    G[b].push_back(a);
  }
  string ans="";
  ans.resize(n);
  sum[0]=ha[0];
  for(int i=1;i<n;i++){
    sum[i]=sum[i-1]+ha[i];
  }
  vector<int> mah;
  for(int i=0;i<n;i++) mah.push_back(i);
  sort(mah.begin(),mah.end(),habitant);
  vector<int> lim;
  lim.push_back(-1); lim.push_back(mah[0]); lim.push_back(n);
  ans[mah[0]]='1';
  for(int i=1;i<n;i++){
    auto it=lower_bound(lim.begin(),lim.end(),mah[i]);
    int r=(*it); it--;
    int l=(*it);
    ll sr=sum[r-1];
    ll sl=0;
    if(l!=-1) sl=sum[l];
    ll s=sr-sl;
    int ml=0,mr=0;
    if(l!=-1) ml=ha[l];
    if(r!=n) mr=ha[r];
    if(l!=-1 && r!=n){ 
      if(s>=ml) ans[mah[i]]=ans[l];
      else{
	if(s>=mr) ans[mah[i]]=ans[r];
	else ans[mah[i]]='0';
      }
    }
    else{
      if(l==-1 && s>=mr) ans[mah[i]]=ans[r];
      else if(r==n && s>=ml) ans[mah[i]]=ans[l];
      else ans[mah[i]]='0';
    }
    lim.push_back(mah[i]);
  }
  /*if(n>2000){
    ans="1";
    dfs(0,0);
    for(int i=1;i<n;i++){
      if(sb[i]>=ha[pa[i]] && ans[pa[i]]=='1') ans+='1';
      else ans+='0';
    }
  }
  else{
    for(int i=0;i<n;i++){
      bfs(i);
      bool all=1;
      for(int j=0;j<n;j++) all&=vis[j];
      if(all) ans+='1';
      else ans+='0';
    }
    }*/
  cout<<ans<<endl;
}

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