HDU - 5950 C - Recursive sequence

C - Recursive sequence

 

矩阵快速幂

 

 

#include<iostream>
#include<cstdio>
#include<algorithm>
#include<cstring>
 using namespace std;
 typedef long long ll;
 const ll mod=2147493647;
struct node
{
    ll ma[11][11];
};
 node mul(node a,node b)
 {
     node ans;
     memset(ans.ma,0,sizeof ans.ma);
    for(int i=0;i<7;i++)
        for(int j=0;j<7;j++)
         for(int k=0;k<7;k++)
            ans.ma[i][j]=(ans.ma[i][j]+a.ma[i][k]*b.ma[k][j])%mod;
    return ans;
 }
 node pow(node a,int b)
 {
     node ans;
     memset(ans.ma,0,sizeof ans.ma);
     for(int i=0;i<7;i++) ans.ma[i][i]=1;
     while(b)
     {
         if(b&1) ans=mul(ans,a);
         a=mul(a,a);
         b>>=1;
     }
     return ans;
 }
int main(){

    node a;
    memset(a.ma,0,sizeof(a.ma));
    a.ma[0][1] = 1;
    a.ma[1][1] = a.ma[1][2] = a.ma[1][6] = 1;
    a.ma[2][2] = a.ma[2][6] = 1;
    a.ma[1][0] = 2; a.ma[1][3] = a.ma[1][5] = a.ma[2][3] = a.ma[2][5] = 4;
    a.ma[1][4] = a.ma[2][4] = 6;
    a.ma[3][3] = a.ma[4][4] = a.ma[5][5] = a.ma[6][6] = 1;
    a.ma[3][6] = a.ma[4][6] = a.ma[5][6] = 1;
    a.ma[3][4] = a.ma[3][5] = 3;
    a.ma[4][5] = 2;
    int t;
    scanf("%d",&t);
    ll n,aa,bb;
    node b;
    while(t--){
        scanf("%lld%lld%lld",&n,&aa,&bb);
        if(n==1){
            printf("%lld\n",aa%mod);
        }
        else if(n==2){
            printf("%lld\n",bb%mod);
        }
        else{

            node ans = pow(a,n-2);
            ll ANS = 0;
            ANS = (ANS+ans.ma[1][0]*aa)%mod;
            ANS = (ANS+ans.ma[1][1]*bb)%mod;
            ANS = (ANS+ans.ma[1][2]*16)%mod;
            ANS = (ANS+ans.ma[1][3]*8)%mod;
            ANS = (ANS+ans.ma[1][4]*4)%mod;
            ANS = (ANS+ans.ma[1][5]*2)%mod;
            ANS = (ANS+ans.ma[1][6]*1)%mod;
            printf("%I64d\n",ANS);
        }
    }
    return 0;
}