quicksort--python--others

来源：互联网发布：信捷plc编程案例编辑：程序博客网时间：2024/06/11 06:53

搜了stackoverflow 上的quicksort, 明白了什么叫elegant, compact code:

def qsort(arr):      if len(arr) <= 1:          return arr     else:          return qsort([x for x in arr[1:] if x<arr[0]]) + [arr[0]] + qsort([x for x in arr[1:] if x>=arr[0]])

Or you can make this a little bit longer to make sense:

def sort(array=[12,4,5,6,7,3,1,15]):    less = []    equal = []    greater = []    if len(array) > 1:        pivot = array[0]        for x in array:            if x < pivot:                less.append(x)            if x == pivot:                equal.append(x)            if x > pivot:                greater.append(x)        # Don't forget to return something!        return sort(less)+ equal +sort(greater)  # Just use the + operator to join lists    # Note that you want equal ^^^^^ not pivot    else:  # You need to hande the part at the end of the recursion - when you only have one element in your array, just return the array.        return array

or this version:

def sort(A):    if len(A) <= 1:        return A    else:        pivot = A[0]                small = []        mid = []        big = []        for item in A:            if item == pivot:                mid.append(item)            elif item > pivot:                big.append(item)            else:                small.append(item)        small = sort(small)        mid = mid  #不能递归sort(mid)，否则当有重复元素时，会死循环        big = sort(big)        A = small + mid + big        return AA = [10,10,11,52,3,8,4,-1]print Aprint sort(A)

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