快速排序

 NSMutableArray *arr = [[NSMutableArray alloc] initWithObjects:@(6), @(1),@(2),@(5),@(9),@(4),@(3),@(7),nil];
 [self quickSortArray:arr withLeftIndex:0 andRightIndex:arr.count - 1];

- (void)quickSortArray:(NSMutableArray *)arr withLeftIndex:(NSInteger)leftIndex andRightIndex:(NSInteger)rightIndex {
    
    if (leftIndex >= rightIndex) {
        return;
    }
    NSInteger i = leftIndex;
    NSInteger j = rightIndex;
    NSInteger key = [arr[i] integerValue];
    while (i < j) {
        while (i < j && [arr[j] integerValue] >= key) {// 从右边开始查找比基准数小的值
            j--;
        }
        // 谷歌币基准数小，则将查找到的小值调换到i的位置
        arr[i] = arr[j];
        
        while (i < j && [arr[i] integerValue] < key) {// 从左边开始查找比基准数大的值
            i++;
        }
        arr[j] = arr[i];
    }
    
    arr[i] = @(key);//将基准数放到正确位置
    // 第一次查找结束后进行左右两边查找，依次类推递归操作
    [self quickSortArray:arr withLeftIndex:leftIndex andRightIndex:i - 1];
    [self quickSortArray:arr withLeftIndex:i + 1 andRightIndex:rightIndex];
    NSLog(@"%@", arr);
}

 arr = [7,5,8,4,3,6,9,2,1]
 print(arr)
 quick_sort(arr,0,len(arr)-1)
 print(arr)

def quick_sort(array,low,high):
    if low >= high:
        return
    i = low
    j = high
    key = arr[i]
    while i < j:

        while i < j and arr[j] >= key :
            j = j - 1

        arr[i] = arr[j]

        while i < j and arr[i] <= key :
            i = i + 1
        arr[j] = arr[i]
    arr[i] = key
    #以上结束一轮

    quick_sort(arr,low,i - 1)
    quick_sort(arr, i + 1, high)