[HDU1575]Tr A（矩阵乘法）

题目描述

代码

#include<iostream>
#include<cstring>
#include<cstdio>
using namespace std;
const int Mod=9973;
const int max_n=15;
int T,n,k,ans;
struct hp{int a[max_n][max_n];}st,m,matrix;

inline hp cheng(hp a,hp b)
{
hp ans;
memset(ans.a,0,sizeof(ans.a));
for (int i=1;i<=n;++i)
for (int j=1;j<=n;++j)
for (int k=1;k<=n;++k)
ans.a[i][j]=(ans.a[i][j]+a.a[i][k]*b.a[k][j]%Mod)%Mod;
return ans;
}
inline hp matrix_fast_pow(hp a,int p)
{
hp ans=st;
for (;p;p>>=1,a=cheng(a,a))
if (p&1)
ans=cheng(ans,a);
return ans;
}
int main()
{
scanf("%d",&T);
while (T--)
{
scanf("%d%d",&n,&k);
memset(st.a,0,sizeof(st.a));
for (int i=1;i<=n;++i) st.a[i][i]=1;
for (int i=1;i<=n;++i)
for (int j=1;j<=n;++j)
scanf("%d",&m.a[i][j]);
matrix=matrix_fast_pow(m,k);
ans=0;
for (int i=1;i<=n;++i)
ans=(ans+matrix.a[i][i])%Mod;
printf("%d\n",ans);
}
}