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hdu------(1757)A Simple Math Problem(简单矩阵快速幂)

A Simple Math Problem

Time Limit: 3000/1000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others)
Total Submission(s): 2791    Accepted Submission(s): 1659


Problem Description
Lele now is thinking about a simple function f(x).

If x < 10 f(x) = x.
If x >= 10 f(x) = a0 * f(x-1) + a1 * f(x-2) + a2 * f(x-3) + …… + a9 * f(x-10);
And ai(0<=i<=9) can only be 0 or 1 .

Now, I will give a0 ~ a9 and two positive integers k and m ,and could you help Lele to caculate f(k)%m.
 

 

Input
The problem contains mutiple test cases.Please process to the end of file.
In each case, there will be two lines.
In the first line , there are two positive integers k and m. ( k<2*10^9 , m < 10^5 )
In the second line , there are ten integers represent a0 ~ a9.
 

 

Output
For each case, output f(k) % m in one line.
 

 

Sample Input
10 99991 1 1 1 1 1 1 1 1 120 5001 0 1 0 1 0 1 0 1 0
 

 

Sample Output
45104
 

 

Author
linle
 

 

Source
2007省赛集训队练习赛(6)_linle专场
 代码:
 1 //#define LOCAL 2 #include<cstdio> 3 #include<cstring> 4 #define LL __int64 5 using namespace std; 6 const int maxn=10; 7 LL k,m; 8 int aa[maxn],mat[maxn][maxn]; 9 int ans[maxn][maxn];10 11 void init()12 {13     for(int i=0;i<10;i++)14     {15      for(int j=0;j<10;j++)16      {17        if(i==0)18          mat[i][j]=aa[j];19        else20           if(i==j+1)mat[i][j]=1;21        else mat[i][j]=0;22        if(i==j)23            ans[i][j]=1;24        else ans[i][j]=0;25      }26     }27 }28 29 void Matrix(int a[][10],int b[][10])30 {31 32      int c[10][10];33      for(int i=0;i<10;i++)34      {35          for(int j=0;j<10;j++)36         {37             c[i][j]=0;38           for(int k=0;k<10;k++)39            {40             c[i][j]=(c[i][j]+a[i][k]*b[k][j])%m;41           }42         }43      }44     for(int i=0;i<10;i++)45     {46       for(int j=0;j<10;j++)47       {48         a[i][j]=c[i][j];49       }50     }51 }52 53 void pow(LL n)54 {55     while(n>0)56     {57         if(n&1) Matrix(ans,mat);58         n>>=1L;59         if(n==0)break;60         Matrix(mat,mat);61     }62 }63 64 int main()65 {66     #ifdef LOCAL67      freopen("test.in","r",stdin);68     #endif69 70   while(scanf("%I64d%I64d",&k,&m)!=EOF)71   {72        for(int i=0;i<10;i++)73        scanf("%d",aa+i);74      if(k<10) printf("%I64d\n",k%m);75      else76      {77        init();78        pow(k-9);79        int res=0;80        for(int i=0;i<10;i++)81         res=(res+(10-i-1)*ans[0][i])%m;82        printf("%d\n",res);83     }84   }85   return 0;86 }
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hdu------(1757)A Simple Math Problem(简单矩阵快速幂)