题解

#include<bits/stdc++.h>
#define ll long long
using namespace std;
ll n;
int main(){
    cin >> n;
    set<ll> a[2];
    for(ll i=1;i<=n;i++){
        ll x;
        cin>>x;
        a[x].insert(i);
    }
    while(!a[0].empty()||!a[1].empty()){
        ll c=1;
        if (a[0].empty()) c=1;
        else if (a[1].empty()) c=0;
        else if (*a[0].begin()<*a[1].begin()) c=0;
        vector<ll> p;
        ll l=0;
        while(1){
            auto it=a[c].upper_bound(l);
            if(it==a[c].end())break;
            p.push_back(*it);
            l=*it;
            a[c].erase(it);
            c=!c;
        }
        for(ll t:p){
            cout<<t<<' ';
        }
        cout << "\n";
    }
	return 0;
}