Mathematician QSC
Time Limit: 2000/1000 MS (Java/Others) Memory Limit: 131072/131072 K (Java/Others)
Total Submission(s): 229 Accepted Submission(s): 114
Through unremitting efforts, one day he finally found the QSC sequence, it is a very magical sequence, can be calculated by a series of calculations to predict the results of a course of a semester of a student.
This sequence is such like that, first of all,f(0)=0,f(1)=1,f(n)=f(n−2)+2∗f(n−1)(n≥2)Then the definition of the QSC sequence is g(n)=∑ni=0f(i)2. If we know the birthday of the student is n, the year at the beginning of the semester is y, the course number x and the course total score s, then the forecast mark is xg(n∗y)%(s+1).
QSC sequence published caused a sensation, after a number of students to find out the results of the prediction is very accurate, the shortcoming is the complex calculation. As clever as you are, can you write a program to predict the mark?
The next T lines were given n, y, x, s, respectively.
n、x is 8 bits decimal integer, for example, 00001234.
y is 4 bits decimal integer, for example, 1234.
n、x、y are not negetive.
1≤s≤100000000
20160830 2016 12345678 666
20101010 2014 03030303 333
317
/*
hdu 5895 广义Fibonacci数列 problem:
求x^g(n*y)%(s+1)的值. f(0)=0,f(1)=1,f(n)=f(n−2)+2∗f(n−1) g(n)是前n项f的平方和 solve:
因为n*y很大,所以可以通过欧拉降幂. 而且找规律发现g(n*y) = f(n*y)*f(n*y+1)/2
所以可以通过矩阵快速幂求出这两个值,然后用求个逆元 hhh-2016-09-19 20:00:04
*/
#pragma comment(linker,"/STACK:124000000,124000000")
#include <algorithm>
#include <iostream>
#include <cstdlib>
#include <cstdio>
#include <cstring>
#include <vector>
#include <math.h>
#include <queue>
#include <set>
#include <map>
#define lson i<<1
#define rson i<<1|1
#define ll long long
#define clr(a,b) memset(a,b,sizeof(a))
#define scanfi(a) scanf("%d",&a)
#define scanfs(a) scanf("%s",a)
#define scanfl(a) scanf("%I64d",&a)
#define scanfd(a) scanf("%lf",&a)
#define key_val ch[ch[root][1]][0]
#define eps 1e-7
#define inf 0x3f3f3f3f3f3f3f3f
using namespace std;
const double PI = acos(-1.0);
ll mod ;
struct Matri
{
ll a[2][2];
};
Matri Mat;
Matri from;
Matri Mul(Matri A,Matri B)
{
Matri c;
for(int i=0; i<2; i++)
{
for(int j=0; j<2; j++)
{
c.a[i][j]=0;
for(int k=0; k<2; k++)
{
c.a[i][j]=(c.a[i][j]+((A.a[i][k]%mod)*(B.a[k][j]%mod)))%mod;
}
}
}
return c;
}
ll Euler (ll n)
{
ll i,ans=n;
for (i=2; i*i<=n; i++) if (n%i==0)
{
ans=ans/i*(i-1);
while (n%i==0) n/=i;
}
if (n>1) ans=ans/n*(n-1);
return ans;
}
Matri Pow(ll n)
{
Matri t ;
Matri ta = Mat ;
t.a[0][0] = t.a[1][1] = 1;
t.a[1][0] = t.a[0][1] = 0;
while(n)
{
if(n & 1) t = Mul(t,ta);
ta = Mul(ta,ta);
n >>= 1;
}
return t;
}
Matri Add(Matri a,Matri b)
{
Matri c;
for(int i=0; i<2; i++)
{
for(int j=0; j<2; j++)
{
c.a[i][j]=a.a[i][j]+b.a[i][j];
c.a[i][j]%=mod;
}
}
return c;
}
ll PowerMod(ll a, ll b, ll c)
{ ll ans = 1;
ll k = a % c;
while(b>0)
{
if(b % 2 == 1)
ans = ((ans%c)*(k%c)) % c;
b = b/2;
k = ((k% c )* (k% c) )% c;
}
return ans; }
void solve(char *s,ll &ans)
{
ans = 0;
for(unsigned int i = 0; i < strlen(s); i++)
{
ans = ans*10 + (s[i] - '0');
}
}
char str1[10],str2[10],str3[10];
int main()
{ ll x,y,s,n;
int T;
scanf("%d",&T);
while(T--)
{
memset(from.a,0,sizeof(from.a));
from.a[0][0] = 1;
Mat.a[0][0] = 2,Mat.a[0][1] = 1,Mat.a[1][1] = 0,Mat.a[1][0] = 1;
scanf("%s%s%s%I64d",str1,str2,str3,&s);
solve(str1,n),solve(str2,y),solve(str3,x);
if(n*y == 0)
{
printf("1\n");
continue;
}
mod = Euler(s+1LL);
mod*=2LL;
Matri tp = Mul(Pow(n*y-1LL),from);
Matri tp1 = Mul(Pow(n*y),from);
ll ta = tp.a[0][0]*tp1.a[0][0]%mod;
ta=ta%(mod)/2LL;
ll to = ta+mod;
printf("%I64d\n",PowerMod(x,to,s+1LL));
}
return 0;
}