快排的思想想必大家都懂，前后两个指针，向中间靠拢。我这个partition函数能保证所有相同的数都被比较一次，靠拢在一起。

代码：

 

public class Main {          public static int[] partition1(int[] arr, int begin, int end, int pivotValue) {        int small = begin-1;        int cur = begin;        int big = end+1;                while(cur!=big) {            if(arr[cur] < pivotValue) {                swap(arr, ++small, cur++);            } else if(arr[cur] > pivotValue) {                swap(arr, cur, --big);            } else {                cur++;            }        }                int[] range = new int[2];        range[0] = small;        range[1] = big;                return range;    }        public static void quickSort(int[] array,int low, int high) {        if(array == null || array.length==0) {            return;        }                if(low>=high) {            return;        }                int[] res = partition1(array, low, high, array[low]);        quickSort(array, low, res[0]);        quickSort(array, res[1], high);    }    public static void main(String[] args) {        int[] a = {34,2,25,1,12,34,12,56,23,15,34,12,12,54,34};        quickSort(a, 0, a.length-1);        for(int i=0; i