HDU5344——数学题——MZL's xor

/*
根据式子可以推出公式为所有值×2的异或和
*/
/************************************************
Author        :powatr
Created Time  :2015-8-5 22:08:30
File Name     :b.cpp
************************************************/

#include <cstdio>
#include <algorithm>
#include <iostream>
#include <sstream>
#include <cstring>
#include <cmath>
#include <string>
#include <vector>
#include <queue>
#include <deque>
#include <stack>
#include <list>
#include <map>
#include <set>
#include <bitset>
#include <cstdlib>
#include <ctime>
using namespace std;

#define lson l, mid, rt << 1
#define rson mid + 1, r, rt << 1 | 1
typedef long long ll;
const int MAX = 1e6 + 10;
const int INF = 0x3f3f3f3f;
const int MOD = 1e9 + 7;

ll a[MAX];
int main(){
    int n, m, z, l;
    int T;
    scanf("%d", &T);
    while(T--){
    scanf("%d%d%d%d", &n, &m, &z, &l);
    a[1] = 0;
        for(int i = 2; i <= n; i++)
            a[i] = (a[i-1]*m + z)%l;
    ll sum = 0;
    for(int i = 1; i <= n; i++)
        sum ^= 1ll*(a[i] << 1);
  printf("%I64d\n", sum);
    }
  return 0;
}