#include<bits/stdc++.h>
using namespace std;
using ll=long long;
using ld=long double;
using pii=pair<int,int>;
#define f first
#define s second
#define pb push_back
#define REP(i,n) for(int i=0;i<n;i++)
#define REP1(i,n) for(int i=1;i<=n;i++)
#define FILL(n,x) memset(n,x,sizeof(n))
#define ALL(_a) _a.begin(),_a.end()
#define sz(x) (int)x.size()
#define SORT_UNIQUE(c) (sort(c.begin(),c.end()),c.resize(distance(c.begin(),unique(c.begin(),c.end()))))
const ll maxn=500+5;
const ll maxlg=__lg(maxn)+2;
const ll INF64=4e18;
const int INF=0x3f3f3f3f;
const ll MOD=1e8+7;
const ld PI=acos(-1);
const ld eps=1e-4;
#define lowb(x) x&(-x)
#define MNTO(x,y) x=min(x,(__typeof__(x))y)
#define MXTO(x,y) x=max(x,(__typeof__(x))y)
int query(string str);
int N,S;
vector<int> ord;
string rec(string pf,string sf,int cur){
//cout<<pf<<' '<<sf<<' '<<cur<<'\n';
bool hv=0;
for(int i=cur;i<S;i++){
string z=pf;
z.pb(ord[i]+'a');
z+=sf;
if(sz(z)<=N and query(z)==sz(z)){
hv=1;
cur=i;
break;
}
}
if(!hv){
//cout<<"NO\n";
return "";
}
int a=1,b=N-sz(pf)-sz(sf);
while(a<b){
int m=(a+b+1)/2;
string z=pf;
REP(j,m) z.pb(ord[cur]+'a');
z+=sf;
if(sz(z)<=N and query(z)==sz(z)) a=m;
else b=m-1;
}
string ans="";
REP(x,a+1){
string z;
REP(y,a-x) z.pb(ord[cur]+'a');
z+=sf;
string tmp=rec(pf+ans,z,cur+1);
ans+=tmp;
ans.pb(ord[cur]+'a');
}
ans.pop_back();
//cout<<pf<<' '<<sf<<' '<<cur;
//cout<<"RETURNED: "<<ans<<'\n';
return ans;
}
string guess(int n, int s){
REP(i,s) ord.pb(i);
shuffle(ALL(ord),rng);
N=n,S=s;
return rec("","",0);
}
Compilation message
password.cpp: In function 'std::string guess(int, int)':
password.cpp:71:19: error: 'rng' was not declared in this scope
71 | shuffle(ALL(ord),rng);
| ^~~
