POJ 3734 Blocks

#include <iostream>
#include <algorithm>
#include <cstdio>
#include <cstring>
#include <queue>
#include <vector>
#include <cmath>
#include <stack>
#include <string>
#include <map>
#include <set>
#define pi acos(-1)
#define LL long long
#define ULL unsigned long long
#define inf 0x3f3f3f3f
#define INF 1e18
#define lson l,mid,rt<<1
#define rson mid+1,r,rt<<1|1
using namespace std;
typedef pair<int, int> P;
const int maxn = 4;
const int mod = 10007;

struct Matrix{
int n, m;
int a[maxn][maxn];
Matrix(){   // 矩阵初始化 (叫做构造函数 会自动执行 我学了c++后才知道的..)
n = m = 0;
memset(a, 0, sizeof(a));
}
Matrix operator * (const Matrix &b) const {
Matrix tmp;
tmp.n = n; tmp.m = b.m;
for (int i = 0; i < n; i++){
for (int j = 0; j < m; j++){
if (!a[i][j]) continue; //稀疏矩阵乘法优化
for (int k = 0; k < b.m; k++){
tmp.a[i][k] = (tmp.a[i][k] + a[i][j] * b.a[j][k]) % mod;
}
}
}
return tmp;
}
};
int fast_muti(int n)
{
Matrix base, ans;
base.n = base.m = 4;
base.a[0][0] = 2; base.a[0][1] = 1; base.a[0][2] = 1; base.a[0][3] = 0;
base.a[1][0] = 1; base.a[1][1] = 2; base.a[1][2] = 0; base.a[1][3] = 1;
base.a[2][0] = 1; base.a[2][1] = 0; base.a[2][2] = 2; base.a[2][3] = 1;
base.a[3][0] = 0; base.a[3][1] = 1; base.a[3][2] = 1; base.a[3][3] = 2;
ans.n = ans.m = 4;
for (int i = 0; i < 4; i++)
ans.a[i][i] = 1;
while (n){
if (n & 1)
ans = base * ans;
base = base * base;
n >>= 1;
}
return ans.a[0][0];
}
int main(void)
{
//  freopen("C:\\Users\\wave\\Desktop\\NULL.exe\\NULL\\in.txt","r", stdin);
int n, T;
cin >> T;
while (T--)
{
cin >> n;
printf("%d\n", fast_muti(n));
}

return 0;
}