HDU 6470 [power] matrix fast

Topic links: http://acm.hdu.edu.cn/showproblem.php?pid=6470

Write this question is to make myself not to forget the power of matrix how quickly launch matrix formulas.

Note that the code is a TLE! !

 1 #include<stdio.h>
 2 #include<string.h>
 3 #define mem(a, b) memset(a, b, sizeof(a))
 4 typedef long long ll;
 5 const int mod = 123456789;
 6 
 7 ll n;
 8 
 9 struct Matrix
10 {
11     ll a[10][10];
12 }A, res, temp;
13 
14 Matrix Multiply(Matrix a, Matrix b)
15 {
16     Matrix ans;
17     mem(ans.a, 0);
18     for(int i = 1; i <= 6; i ++)
19         for(int j = 1; j <= 6; j ++)
20             for(int k = 1; k <= 6; k ++)
21             {
22                 ans.a[i][j] += a.a[i][k] * b.a[k][j] % mod;
23                 ans.a[i][j] %= mod;
24             }
25     return ans;
26  }
 27  
28  int main ()
 29  {
 30      mem (Aa, 0 );   // Structures Nori阵
31      Aa [ 1 ] [ 2 ] = Aa [ 2 ] [ 2 ] = Aa [ 2 ] [ 3 ] = Aa [ 3 ] [ 3 ] = Aa [ 3 ] [ 6 ] = Aa [ 4 ] [ 4 ] = Aa [ 4 ] [ 6 ] = Aa [ 5 ] [ 5 ] = Aa [ 5 ] [ 6 ] = Aa [ 6][6] = 1;
32     A.a[2][1] = A.a[4][5] = 2;
33     A.a[3][4] = A.a[3][5] = 3;
34     int T;
35     scanf("%d", &T);
36     while(T --)
37     {
38         temp = A;  //初始化temp矩阵 
39         mem(res.a, 0 ); // initialize the unit matrix 
40          for ( int I = . 1 ; I <= . 6 ; I ++ )
 41 is              res.a [I] [I] = . 1 ;
 42 is          Scanf ( " % LLD " , & n-) ;
 43 is          n-- = 2 ;
 44 is          the while (n-)
 45          {
 46 is              IF (% n- 2 )
 47                  RES = the Multiply (RES, TEMP);
 48              TEMP = the Multiply (TEMP, TEMP);
 49             n /= 2;
50         }
51         printf("%lld\n", (1 * res.a[2][1] % mod + 2 * res.a[2][2] % mod + 27 * res.a[2][3] % mod + 9 * res.a[2][4] % mod + 3 * res.a[2][5] % mod + res.a[2][6] % mod) % mod);
52     }
53     return 0;
54 }

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