提交时间:2026-04-11 18:42:09
运行 ID: 41242
#include<bits/stdc++.h> // #define int long long #define PII pair<int,int> #define fir first #define sec second using namespace std; const int N=1e6+7; int n; set<PII> st[N];//每行所选的元素 bool Ans[N]; int x[N],y[N],bel[N]; vector<PII> P[N];//每列的所有点 int l[N],r[N];//每列的顶/底 queue<int> Q;//不合法的行 inline void Ins(int i){ Ans[i]=1; st[y[i]].emplace(PII(x[i],i)); if(st[y[i]].size()>2)Q.push(y[i]); } inline void Del(int i){ Ans[i]=0; st[y[i]].erase(PII(x[i],i)); } inline void Pop(){ // for(int i=1;i<=n;i++)cout<<Ans[i];cout<<endl; int u=Q.front();Q.pop(); // cout<<u<<endl; if(st[u].size()<=2)return; auto it=st[u].begin();it++; int p=(*it).sec; if(l[x[p]]==r[x[p]]){Del(p);} else if(l[x[p]]==bel[p]){ Del(p);l[x[p]]++;assert(l[x[p]]<P[x[p]].size()); Ins(P[x[p]][l[x[p]]].sec); }else{ Del(p);r[x[p]]--;assert(r[x[p]]>=0); Ins(P[x[p]][r[x[p]]].sec); } if(st[u].size()>2)Q.push(u); } inline void Init(){ for(int i=1;i<=n;i++){ P[x[i]].push_back(PII(y[i],i)); } for(int i=1;i<=1e6;i++)sort(P[i].begin(),P[i].end()); for(int i=1;i<=1e6;i++){ if(P[i].size()){ l[i]=0,r[i]=(int)P[i].size()-1; for(int j=0;j<P[i].size();j++)bel[P[i][j].sec]=j; } } for(int i=1;i<=1e6;i++){ if(P[i].size())Ins(P[i][l[i]].sec),Ins(P[i][r[i]].sec); } } signed main(){ #ifndef ONLINE_JUDGE freopen("cons.in","r",stdin); freopen("cons.out","w",stdout); #endif cin>>n; for(int i=1;i<=n;i++)cin>>x[i]>>y[i]; Init(); while(!Q.empty())Pop(); for(int i=1;i<=n;i++)cout<<Ans[i]; cout<<endl; return 0; }