/* File: MatMult.java

   Straightforward single thread matrix multiplication.
   Computes C = A x B for NxN matrices
*/

import java.util.* ;

public class MatMult {

   public static void main (String [] args) {

      int N = 2000 ;

      int[][] A = new int[N][N] ;
      int[][] B = new int[N][N] ;
      int[][] C = new int[N][N] ;

      // Random prg = new Random ( System.currentTimeMillis() ) ;
      Random prg = new Random ( 95762 ) ;

      // Populate A and B matrices
      for (int i = 0 ; i < N ; i++ ) {
         for (int j = 0 ; j < N ; j++) {
            A[i][j] = prg.nextInt(N) ;      
            B[i][j] = prg.nextInt(N) ;      
         }
      }


      // Do the N^3 time algorithm
      int sum ;
      for (int i = 0 ; i < N ; i++) {
         for (int j = 0 ; j < N ; j++) {
            sum = 0 ;
            for (int k = 0 ; k < N ; k++) {
               sum += A[i][k] * B[k][j] ;
            }
            C[i][j] = sum ;
         }
      }


/*
      // Print out C for debugging. 
      // Skip for big matrices.
      //
      for (int i = 0 ; i < N ; i++) {
         for (int j = 0 ; j < N ; j++) {
            System.out.print("[" + C[i][j] + "]") ;
         }
         System.out.println() ;
      }
*/

   }
    
}