Java实现蓝桥杯VIP 算法训练 矩阵乘方

import java.util.Scanner;


public class 矩阵乘方 {
	public static void main(String[] args) {
		Scanner scanner = new Scanner(System.in);
		int N = scanner.nextInt();					//N阶
		int M = scanner.nextInt();					//M次幂
		int[][] a = new int[N][N];					//用二维数组a接收矩阵A
		int[][] c = new int[N][N];					//二维数组c接收矩阵A,并用于存储结果矩阵
		int i,j;
		
		//用二维数组a接收矩阵A
		for (i = 0; i < N; i++) {
			for (j = 0; j < N; j++) {
				a[i][j] = c[i][j]= scanner.nextInt();
			}
		}
		
		//矩阵乘法
		if (M == 0) {								//当M=0时结果为单位矩阵
			for (i = 0; i < N; i++) {
				for(j = 0; j < N; j++) {
					if (i == j) {
						System.out.print(1 + " ");
					} else {
						System.out.print(0 + " ");
					}
				}
				System.out.println();
			}
		} else if (M == 1) {						//当M=1时结果为原来的矩阵
			for (i = 0; i < N; i++) {
				for(j = 0; j < N; j++) {
					System.out.print(c[i][j] + " ");
				}
				System.out.println();
			}
		} else {									//当M>1时即为M个矩阵A相乘的结果。
			for (int m = 1; m < M; m++) {						//最外层控制M次幂，m从1开始或m<M -1都可以，不要乘多一次
				int[][] temp = new int[N][N];
				for (i = 0; i < N; i++) {						//i控制行
					for (j = 0; j < N; j++) {					//j控制列
						int sum = 0;
						for (int k = 0; k < N; k++) {
							sum += a[i][k] * c[k][j];							
						}										
						temp[i][j] = sum;
					}					
				}
				c = temp;
			}			
			//打印结果矩阵C
			for (i = 0; i < N; i++) {
				for (j = 0; j < N; j++) {
					System.out.print(c[i][j] + " ");
				}
				System.out.println();
			}
		}		
	}

}