数组小工具2

整形的数组小工具

package algorithms.self.tools;

import java.util.Arrays;

/**
 * This is a class to implement Integer array tools
 * 
 * @author ygh 2017年3月14日
 */
public class IntegerArrayTools {

    /**
     * Print a int[] into console
     * 
     * @param arr The array need to print
     */
    public static void toStringIntArray(int[] arr) {
        System.out.println(Arrays.toString(arr));
    }

    /**
     * Print a int[][] into console
     * 
     * @param arr The array need to print
     */
    public static void toTwoDimensionalString(int[][] arr) {
        int row = arr.length;
        for (int i = 0; i < row; i++) {
            toStringIntArray(arr[i]);
        }
    }

    /**
     * Get a random array by size and max value
     * 
     * @param size The size the new array you want to create
     * @param maxValue The max value in the array;
     * @return A random array
     */
    public static int[] getRandomArray(int size, int maxValue) {
        int[] arr = new int[size];
        for (int i = 0; i < size; i++) {
            arr[i] = getIntRandomValue(maxValue);
        }
        return arr;
    }

    /**
     * Get a random that less than max value
     * 
     * @param maxValue The max value you get the random number
     * @return A random number less than max value
     */
    public static int getIntRandomValue(int maxValue) {
        return (int) (Math.random() * maxValue);
    }

    /**
     * Get a random value in a integer array
     * 
     * @param arr A value come from this array
     * @return A random value comes from this array
     */
    public static int getRandomValue(int[] arr) {
        int length = arr.length;
        return (arr[getIntRandomValue(length)]);
    }

    /**
     * Get the max value in a Array.
     * 
     * @param arr[] The max value come from
     * @return The max value in this array
     */
    public static int getMaxValue(int arr[]) {
        int max = arr[0];
        for (int i = 1; i < arr.length - 1; i++) {
            if (max < arr[i]) {
                max = arr[i];
            }
        }
        return max;
    }

    /**
     * Get a two-dimensional integer array
     * 
     * @param row The size of row
     * @param column The size of column
     * @param maxValue The max value in this array
     * @return a new two-dimensional integer array
     */
    public static int[][] getRandomTwoDimensionalArray(int row, int column, int maxValue) {
        int[][] arr = new int[row][column];
        for (int i = 0; i < row; i++) {
            arr[i] = getRandomArray(column, maxValue);
        }

        return arr;
    }

    /**
     * Get average of an integer array
     * 
     * @param arr The array provide data
     * @return The average of this array
     */
    public static double getArrayAverage(int[] arr) {
        int length = arr.length;
        int sum = 0;
        for (int i = 0; i < length; i++) {
            sum += arr[i];
        }
        return (sum / length);
    }

    /**
     * Copy an array to new array
     * 
     * @param arr The array needed to copy
     * @return The copied array
     */
    public static int[] copy(int arr[]) {
        int length = arr.length;
        int newArr[] = new int[length];
        for (int i = 0; i < length; i++) {
            newArr[i] = arr[i];
        }
        return newArr;
    }

    /**
     * Reverse the elements within an array
     * 
     * @param arr An array want to reverse all elements
     */
    public static void reverse(int[] arr) {
        int tmp;
        int length = arr.length;
        for (int i = 0; i < length / 2; i++) {
            tmp = arr[i];
            arr[i] = arr[length - 1 - i];
            arr[length - 1 - i] = tmp;
        }
    }

    /**
     * Transpose a two-dimensional square array
     * 
     * @param arr
     */
    public static void transposition(int[][] arr) {
        int row = arr.length;
        int temp;
        for (int i = 0; i < row; i++) {
            for (int j = 0; j < i; j++) {
                temp = arr[i][j];
                arr[i][j] = arr[j][i];
                arr[j][i] = temp;
            }
        }
    }

    /**
     * Get a integer array sum
     * @param arr The array to provide the data
     * @return The sum of all elements in the array
     */
    public static int getIntegrArraySum(int arr[]) {
        int sum = 0;
        for (int i = 0; i < arr.length; i++) {
            sum = sum + arr[i];
        }
        return sum;
    }

}