字符串二分查找、快速排序

版权声明：本文为博主原创文章，未经博主允许不得转载。 https://blog.csdn.net/qq_35917800/article/details/87723371

public class Main {
    /**
     * 字符串的二分查找
     * @param str
     * @param strs
     * @return
     */
    public static int binarySearch(String str, String[] strs) {
        int low = 0, high = strs.length - 1;
        while (low <= high) {
            int middle = (low + high) >>> 1;
            int temp = strs[middle].compareTo(str);
            if (temp < 0)
                low = middle + 1;
            else if (temp > 0)
                high = middle - 1;
            else
                return middle;
        }
        return -1;
    }

    /**
     * 快速排序
     * @param arr
     * @param low
     * @param high
     */
    public static void quickSort(int[] arr, int low, int high) {
        if (low >= high) {
            return;
        }
        int i = low;
        int j = high;
        int index = arr[i];
        while (i < j) {
            while (i < j && arr[j] >= index)
                j--;
            if (i < j)
                arr[i++] = arr[j];
            while (i < j && arr[i] < index)
                i++;
            if (i < j)
                arr[j--] = arr[i];
        }
        arr[i] = index;
        quickSort(arr, low, i - 1);
        quickSort(arr, i + 1, high);
    }

    public static void main(String[] args) {
        String[] strs = {"asd", "eqw", "asddsf", "qwe", "fdv", "gdf", "re", "opm"};
        Arrays.sort(strs);
        System.out.println(Arrays.toString(strs));
        System.out.println(binarySearch("opm", strs));

        int[] arr = {72, 6, 57, 88, 60, 42};
        Arrays.sort(args);
        System.out.println(Arrays.toString(arr));
        quickSort(arr, 0, arr.length - 1);
        System.out.println(Arrays.toString(arr));
    }
}

打印结果：

[asd, asddsf, eqw, fdv, gdf, opm, qwe, re]
5
[72, 6, 57, 88, 60, 42]
[6, 42, 57, 60, 72, 88]