Sliding Window Xor

1#include<bits/stdc++.h>
2using namespace std;
3#define int long long
4signed main(){
5  ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
6  int n,k; cin>>n>>k;
7  int x,a,b,c; cin>>x>>a>>b>>c;
8  queue<int> q;
9  int ans=0;
10  for(int i=0,run=x;i<n;run^=(x=(a*x+b)%c),++i){
11    q.emplace(x);
12    if((int)q.size()>k) run^=q.front(),q.pop();
13    if((int)q.size()==k) ans^=run;
14  }
15  cout<<ans<<'\n';
16  return 0;
17}