Description
Let {xi} be the infinite sequence of integers:
1) x0 = A;
2) xi = (alpha * xi-1^2 + beta * xi-1 + gamma) mod M, for i >= 1.
Your task is to find xk if you know A, alpha, beta, gamma, M and k.
1) x0 = A;
2) xi = (alpha * xi-1^2 + beta * xi-1 + gamma) mod M, for i >= 1.
Your task is to find xk if you know A, alpha, beta, gamma, M and k.
Input
Given A (1 <= A <= 10000), alpha (0 <= alpha <= 100), beta (0 <= beta <= 100), gamma (0 <= gamma <= 100), M (1 <= M <= 1000), k (0 <= k <= 10^9). All numbers are integer.
Output
Write xk.
Sample Input
Input
1 1 1 1 10 1
Output
3
2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 /********************** 打表观察,一个周期问题,暴力找周期 ,巧用map找周期 ********************************/ #include"iostream" #include"map" #include"cstdio" using namespace std; const int ms=1100; int T,begin,A,a,b,c,m,k; void find() { map<int, int> mp; //map[0]=A; mp[1]=A; int tmp=A; for(int i=2;i<=ms;i++) { tmp=(a*tmp*tmp+b*tmp+c)%m; if(mp[tmp]) { begin=mp[tmp]; T=i-mp[tmp]; break; } else { mp[tmp]=i; } } } int main() { scanf("%d%d%d%d%d%d",&A,&a,&b,&c,&m,&k); find(); int ans; if(k<begin) { ans=A; for(int i=1;i<=k;i++) ans=((long long)a*ans*ans+b*ans+c)%m; cout<<ans<<endl; } else { k-=begin;k%=T;ans=A; for(int i=1;i<=begin+k;i++) { ans=(a*ans*ans+b*ans+c)%m; } cout<<ans<<endl; } return 0; }