hdu 1575(矩阵快速幂)

题解：矩阵快速幂模板题。

#include <stdio.h>
#include <string.h>
const int N = 10;
struct Mat {
    int g[N][N];
}res, ori;
int n, k;

Mat multiply(Mat x, Mat y) {
    Mat temp;
    memset(temp.g, 0, sizeof(temp.g));
    for (int i = 0; i < n; i++)
        for (int j = 0; j < n; j++)
            for (int l = 0; l < n; l++)
                temp.g[i][j] = (temp.g[i][j] + x.g[i][l] * y.g[l][j]) % 9973;
    return temp;
}

void calc(int m) {
    while (m) {
        if (m & 1)
            res = multiply(res, ori);
        m >>= 1;
        ori = multiply(ori, ori);
    }
}

int main() {
    int t;
    scanf("%d", &t);
    while (t--) {
        memset(res.g, 0, sizeof(res.g));
        memset(ori.g, 0, sizeof(ori.g));
        scanf("%d%d", &n, &k);
        for (int i = 0; i < n; i++) {
            res.g[i][i] = 1;
            for (int j = 0; j < n; j++)
                scanf("%d", &ori.g[i][j]);
        }
        calc(k);
        int ans = 0;
        for (int i = 0; i < n; i++)
            ans = (ans + res.g[i][i]) % 9973;
        printf("%d\n", ans);
    }
    return 0;
}