蓝桥网试题 java 基础练习 矩阵乘法

 1 import java.util.*;
 2 public class Main {
 3     public static void main(String[] args) {
 4         Scanner sc = new Scanner(System.in);
 5         int n = sc.nextInt();
 6         int m = sc.nextInt();
 7         long[][] a = new long[n][n];
 8         long[][] b = new long[n][n];
 9         int i,j;
10         for(i=0;i<n;i++)
11             for(j=0;j<n;j++)
12                 b[i][j]=a[i][j] = sc.nextLong();
13         if(m==0)
14             for(i=0;i<n;i++){
15                 for(j=0;j<n;j++){
16                     if(i==j)System.out.print(1+" ");
17                     else System.out.print(0+" ");
18                 }
19                 System.out.println();
20             }
21         else if(m==1)
22             for(i=0;i<n;i++){
23                 for(j=0;j<n;j++)
24                     System.out.print(a[i][j]+" ");
25                 System.out.println();
26             }
27         else{
28             for(int z=1;z<m;z++){
29                 long[][] tmp = new long[n][n]; 
30                 for(i=0;i<n;i++){
31                     for(j=0;j<n;j++){
32                         long add = 0;
33                         for(int y=0;y<n;y++){
34                             add += a[i][y]*b[y][j];
35                         }
36                         tmp[i][j] = add;
37                     }
38                 }
39                 b = tmp;
40             }
41             for(i=0;i<n;i++){
42                 for(j=0;j<n;j++)
43                     System.out.print(b[i][j]+" ");
44                 System.out.println();
45             }
46         }
47             
48     }
49 }