POJ 3070 矩阵快速幂

#include <cstdio>
#include <iostream>
using namespace std;
const int MOD = 10000;
int n;
struct matrix
{
    int m[2][2];
} ans, base;

matrix multi(matrix a, matrix b)
{
    matrix tmp;
    for (int i = 0; i < 2; ++i)
    {
        for (int j = 0; j < 2; ++j)
        {
            tmp.m[i][j] = 0;
            for (int k = 0; k < 2; ++k)
                tmp.m[i][j] = (tmp.m[i][j] + a.m[i][k] * b.m[k][j]) % MOD;
        }
    }
    return tmp;
}
int fast_mod(int n)
{
    base.m[0][0] = base.m[0][1] = base.m[1][0] = 1;
    base.m[1][1] = 0;
    ans.m[0][0] = ans.m[1][1] = 1;
    ans.m[0][1] = ans.m[1][0] = 0;
    while (n)
    {
        if (n & 1)
        {
            ans = multi(ans, base);
        }
        base = multi(base, base);
        n >>= 1;
    }
    return ans.m[0][1];
}
int main(int argc, char const *argv[])
{
    while (scanf("%d", &n) && n != -1)
        printf("%d\n", fast_mod(n));
    return 0;
}

套用模板就可以了。