poj 3070 矩阵快速幂模板

题意：求fibonacci数列第n项

 #include "iostream"
 #include "vector"
 #include "cstring"
 using namespace std;

 typedef unsigned long int ULL;
 typedef vector<ULL> vec;
 typedef vector<vec> mat;
 const ULL P=;
 int n,m;

 mat mul(mat &A,mat &B)      //return A*B
 {
     mat C(A.size(),vec(B[].size()));
     for (int i=;i<(int)A.size();i++)
     {
         for (int k=;k<(int)B.size();k++)
         {
             for (int j=;j<(int)B[].size();j++)
             {
                 C[i][j]=(C[i][j]+A[i][k]*B[k][j])%P;
             }
         }
     }
     return C;
 }

 mat m_pow(mat A,int m)      //return A^m
 {
     mat B(A.size(),vec(A.size()));
     for (int i=;i<(int)A.size();i++)
         B[i][i]=;
     while (m>)
     {
         if (m&)    B=mul(B,A);
         A=mul(A,A);
         m>>=;
     }
     return B;
 }

 int main()
 {
     while (cin>>n)
     {
         if (n==-)  break;
         mat A(,vec());

         A[][]=;  A[][]=;
         A[][]=;  A[][]=;

         A=m_pow(A,n);
         cout<<A[][]<<endl;
     }
 }