阿健的刷题库函数|MyArrays

package wsj;

/**
 * 当前类所有函数 
 * ------------- 
 * 交换[范型]数组：swap() 
 * 打印一维[范型]数组：printArr1D()
 * 打印二维[范型]数组：printArr2D()
 * 冒泡排序一维[整型]数组，返回排序后的索引：BubbleSort1D() 
 * 冒泡排序一维[字符串型]数组，返回排序后的索引：BubbleSort1D()
 * 根据二维[整型]数组第一行进行冒泡排序：BubbleSort2D() 
 * 根据二维[字符串型]数组第一行进行冒泡排序：BubbleSort2D()
 */

public class MyArrays {
    // 交换数组
    public static <T> void swap(T[] arr, int i, int j) {
        T tmp;
        tmp = arr[i];
        arr[i] = arr[j];
        arr[j] = tmp;
    }

    // 打印一维数据
    public static <T> void printArr1D(T[] arr) {
        String s = "[" + arr[0];
        for (int i = 1; i < arr.length; i++) {
            s += ", " + arr[i];
        }
        s += "]";
        System.out.println(s);
    }

    // 打印二维数据
    public static <T> void printArr2D(T[][] arr) {
        for (int i = 0; i < arr.length; i++) {
            for (int j = 0; j < arr[0].length; j++) {
                if (j < arr[0].length - 1) {
                    System.out.print(arr[i][j] + ",");
                } else {
                    System.out.print(arr[i][j] + "\n");
                }
            }
        }
        System.out.println();
    }

    // 冒泡排序一维整型数组，返回排序后的索引
    public static Integer[] BubbleSort1D(Integer[] arr) {
        if (arr == null || arr.length < 2) {
            return null;
        }
        if (arr.length < 2) {
            return new Integer[1];
        }
        Integer[] arrInd = new Integer[arr.length];
        for (int i = 0; i < arr.length; i++) {
            arrInd[i] = i;
        }
        for (int i = 0; i < arr.length; i++) {
            for (int j = 0; j < arr.length - 1 - i; j++) {
                if (arr[j] > arr[j + 1]) {
                    swap(arr, j, j + 1);
                    swap(arrInd, j, j + 1);
                }
            }
        }
        return arrInd;
    }

    // 冒泡排序一维字符串型数组，返回排序后的索引
    public static Integer[] BubbleSort1D(String[] arr) {
        if (arr == null || arr.length < 2) {
            return null;
        }
        if (arr.length < 2) {
            return new Integer[1];
        }
        Integer[] arrInd = new Integer[arr.length];
        for (int i = 0; i < arr.length; i++) {
            arrInd[i] = i;
        }
        for (int i = 0; i < arr.length; i++) {
            for (int j = 0; j < arr.length - 1 - i; j++) {
                if  + 1]) > 0) {
                    swap(arr, j, j + 1);
                    swap(arrInd, j, j + 1);
                }
            }
        }
        return arrInd;
    }

    // 根据二维整型数组第一行进行冒泡排序
    public static void BubbleSort2D(Integer[][] arr) {
        Integer[] arrInd = BubbleSort1D(arr[0]);
        int[] help = new int[arr[0].length];
        for (int i = 0; i < help.length; i++) {
            help[i] = arr[1][arrInd[i]];
        }
        for (int i = 0; i < help.length; i++) {
            arr[1][i] = help[i];
        }
    }

    // 根据二维字符串型数组第一行进行冒泡排序
    public static void BubbleSort2D(String[][] arr) {
        Integer[] arrInd = BubbleSort1D(arr[0]);
        String[] help = new String[arr[0].length];
        for (int i = 0; i < help.length; i++) {
            help[i] = arr[1][arrInd[i]];
        }
        for (int i = 0; i < help.length; i++) {
            arr[1][i] = help[i];
        }
    }

    public static void main(String[] args) {
        Integer[][] arr = { { 3, 2, 1, 4 }, { 5, 4, 3, 6 } };
        BubbleSort2D(arr);
        printArr2D(arr);

        String[][] strings = { { "wsj", "hello", "abc", "abd" },
                { "1", "2", "3", "4" } };
        BubbleSort2D(strings);
        printArr2D(strings);
    }
}