src/com/github/puzzles/util/Matrices.java

   1 package com.github.puzzles.util;
   2
   3 import java.util.Arrays;
   4
   5 public class Matrices {
   6
   7     //Don't let anyone instance this class.
   8     private Matrices() {
   9     }
  10
  11     /**
  12      * Copy 2 dimensions array.
  13      *
  14      * @param original the matrix which you want make a copy of it.
  15      * @return the new copy.
  16      */
  17     public static <T> T[][] copyOf(T[][] original, int colsLength, int rowsLength) {
  18         T[][] returnedPuzzle = Arrays.copyOf(original, colsLength);
  19         for (int i = 0; i < colsLength; i++) {
  20             returnedPuzzle[i] = Arrays.copyOf(original[i], rowsLength);
  21         }
  22
  23         return returnedPuzzle;
  24     }
  25
  26     public static <T> T[][] copyOf(T[][] original) {
  27         if (original.length < 0) {
  28             return null;
  29         }
  30         return copyOf(original, original.length, original[0].length);
  31     }
  32
  33     /**
  34      * Fill a value in a matrix.
  35      *
  36      * @param matrix the matrix which you want to fill in it.
  37      * @param val the value which you want fill it in the matrix.
  38      */
  39     public static <T> void fill(T[][] matrix, T val) {
  40         for (int i = 0; i < matrix.length; i++) {
  41             Arrays.fill(matrix[i], val);
  42         }
  43     }
  44
  45     public static <T> int getWidth(T[][] matrix) {
  46         if (matrix != null) {
  47             return matrix.length;
  48         }
  49         return 0;
  50     }
  51
  52     public static <T> int getHeight(T[][] matrix) {
  53         if ((getWidth(matrix) != 0) && (matrix[0] != null)) {
  54             return matrix[0].length;
  55         }
  56         return 0;
  57     }
  58
  59     //Swap two elements with XOR swap algorithm.
  60     public static void swap(Integer[][] matrix, int fromX, int fromY, int toX, int toY){
  61         matrix[fromX][fromY] = matrix[fromX][fromY] ^ matrix[toX][toY];
  62         matrix[toX][toY] = matrix[fromX][fromY] ^ matrix[toX][toY];
  63         matrix[fromX][fromY] = matrix[fromX][fromY] ^ matrix[toX][toY];
  64     }
  65
  66 }