Matrix multiplication

Time Limit: 4000/2000 MS (Java/Others)    Memory Limit: 131072/131072 K (Java/Others)

Total Submission(s): 820    Accepted Submission(s): 328

Problem Description

Given two matrices A and B of size n×n, find the product of them.

bobo hates big integers. So you are only asked to find the result modulo 3.

 

 

Input

The input consists of several tests. For each tests:

The first line contains n (1≤n≤800). Each of the following n lines contain n integers -- the description of the matrix A. The j-th integer in the i-th line equals A

_ij. The next n lines describe the matrix B in similar format (0≤A

_ij,B

_ij≤10

⁹).

 

 

Output

For each tests:

Print n lines. Each of them contain n integers -- the matrix A×B in similar format.

 

 

Sample Input

1 0 1 2 0 1 2 3 4 5 6 7

 

 

Sample Output

0 0 1 2 1

 

 

Author

Xiaoxu Guo (ftiasch)

 

 

Source

 

 

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Mean:

给你两个矩阵，计算两个矩阵的积。

 

nalyse:

很多人认为这题用暴力过不了，时间复杂度为O(n^3),800^3=512000000，差不多要接近于10^9了，可能是hdu的评测速度给力吧，再加上这题是单点评测，每个评测点的时限都有2000ms，所以说暴力过了也实属正常。

 

Time complexity：O(n^3)

 

Source code：

#include
     
      int a[800][800],b[800][800],c[800][800],n,i,j,k;int main(){    while(scanf("%d",&n)!=EOF){        for(i=0;i