Quick sort

public static void quickSort(int[] arr,int begin,int end){
    if(begin>end)
        return;
    int tmp = arr[begin];
    int i =begin;
    int j =end;
    while (i<j){
        while(arr[j]>=tmp && j>i){
            j--;
        }
        arr[i] = arr[j];
        while(arr[i]<=tmp && j>i){
            i++;
        }
        arr[j] = arr[i];
    }
    arr[i] = tmp;
    quickSort(arr, begin, i-1);
    quickSort(arr, i+1, end);
}