常见的排序法_2019-10-13

• 插入排序法
• 选择排序法
• 冒泡排序法

import java.util.Random;

/**
 * @author NOknow
 * @version 1.0
 * @CreateDate 2019/10/12
 * @Desc
 */
public class SoutFunction {

    public static void main(String[] args) {
        int[] dataSrc = getRandomIntArray(10, 100);
        print("dataSrc      ", dataSrc);

        bubbleSort(dataSrc);
        print("bubbleSort   ", dataSrc);

        selectionSort(dataSrc);
        print("selectionSort", dataSrc);

        insertionSort(dataSrc);
        print("insertionSort", dataSrc);
    }

    private static int[] getRandomIntArray(int count, int maxNum) {
        int[] nums = new int[count];
        Random random = new Random();
        random.setSeed(System.currentTimeMillis());
        int i = 0;
        while (i < count) {
            nums[i++] = random.nextInt(maxNum + 1);
        }
        return nums;
    }

    /**
     * 插入排序法
     *
     * @param dataSrc 要进行排序整型数据源
     */
    private static void insertionSort(int[] dataSrc) {
        for (int i = 1; i < dataSrc.length; i++) {
            for (int j = i; j > 0; j--) {
                if (dataSrc[j] < dataSrc[j - 1]) {
                    int temp = dataSrc[j - 1];
                    dataSrc[j - 1] = dataSrc[j];
                    dataSrc[j] = temp;
                }
            }
        }
    }

    /**
     * 选择排序法
     *
     * @param dataSrc 要进行排序整型数据源
     */
    public static void selectionSort(int[] dataSrc) {
        for (int i = 0; i < dataSrc.length; i++) {
            int minIndex = i;
            for (int j = i + 1; j < dataSrc.length; j++) {
                if (dataSrc[minIndex] > dataSrc[j]) {
                    minIndex = j;
                }
            }
            if (minIndex != i) {
                int temp = dataSrc[minIndex];
                dataSrc[minIndex] = dataSrc[i];
                dataSrc[i] = temp;
            }
        }
    }

    /**
     * 冒泡排序法（升序）
     *
     * @param dataSrc 要进行排序整型数据源
     */
    public static void bubbleSort(int[] dataSrc) {
        for (int i = 0; i < dataSrc.length; i++) {
            for (int j = i + 1; j < dataSrc.length; j++) {
                if (dataSrc[i] > dataSrc[j]) {//这里换成小于号就是降序排序
                    int temp = dataSrc[i];
                    dataSrc[i] = dataSrc[j];
                    dataSrc[j] = temp;
                }
            }
        }
    }

    private static void print(String tip, int[] data) {
        System.out.print(tip + " : ");
        for (int i = 0; i < data.length; i++) {
            System.out.print(data[i] + "\t");
        }
        System.out.println();
    }
}