Hdu-5344 MZL's xor

Problem Description

MZL loves xor very much.Now he gets an array A.The length of A is n.He wants to know the xor of all (Ai+Aj)(1≤i,j≤n)
The xor of an array B is defined as B1 xor B2...xorBn

 

Input

Multiple test cases, the first line contains an integer T(no more than 20), indicating the number of cases.
Each test case contains four integers:n,m,z,l
A1=0,Ai=(Ai−1∗m+z)modl
1≤m,z,l≤5∗105,n=5∗105

 

Output

For every test.print the answer.

 

Sample Input

23 5 5 76 8 8 9

 

Sample Output

1416

 

Author

SXYZ

 

Source

2015 Multi-University Training Contest 5

 

Recommend

wange2014

分析：超级水题，比赛时看错题了。

#include <cstdio>#include <iostream>using namespace std;int T;long long n,m,z,l;int main(){cin.sync_with_stdio(false);cin>>T;while(T--){cin>>n>>m>>z>>l;long long x = 0,ans = 0;for(int i = 2;i <= n;i++){x = (x*m + z) % l;ans = ans ^ x;}cout<<ans*2<<endl;}}