紧急求救！！！！

飒然 2007-08-05 03:14:33

Description

You are given three n × n matrices A, B and C. Does the equation A × B = C hold true?

Input

The first line of input contains a positive integer n (n ≤ 500) followed by the the three matrices A, B and C respectively. Each matrix's description is a block of n × n integers.

It guarantees that the elements of A and B are less than 100 in absolute value and elements of C are less than 10,000,000 in absolute value.

Output

Output "YES" if the equation holds true, otherwise "NO".

Sample Input

2
1 0
2 3
5 1
0 8
5 1
10 26

Sample Output

YES
我的程序：这是矩阵相乘的问题，谁有高效算法吗？？？求救啊
import java.util.*;

public class Main1{
public static void main(String[] args){
Scanner s = new Scanner(System.in);
int n = s.nextInt();
int k = 3*n;
int[][] a = new int[k][k];
int p = 0;
for (int j = 0;j < k;j++){
for(int m = 0; m < n;m++){
a[j][m] = s.nextInt();
if (j > 2*n){
int q = 0;
for(int e = 0;e < n;e++){
q = q+a[j-2*n][e]*a[e+n][m];
}
if (a[j][m]!=q){
p++;break;
}
}
}
if (p!=0) break;
}
if (p!=0) System.out.println("NO");
else System.out.println("YES");
}
}

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