leetcode常规算法题复盘（基础篇）——十大排序算法（二）

 

  ##############################
 #        6、快速排序          #
#############################
def QuickSort(array,left,right):
    lenth = len(array)
    left = left if type(left) is int else 0 
    right = right if type(right) is int else lenth-1 
    if left<right:
        partitionIndex = partition(array,left,right)
        QuickSort(array,left,partitionIndex-1)
        QuickSort(array,partitionIndex+1,right)
    return array

def partition(array,left,right):
    pivot = left
    index = pivot+1
    for i in range(index,right+1):
        if array[i]<array[pivot]:
            temp = array[i]
            array[i] = array[index]
            array[index] = temp
            index += 1
    temp = array[pivot]
    array[pivot] = array[index-1]
    array[index-1] = temp
    return index-1

 

 

  ##############################目前还有些问题
 #         7、堆排序           #
#############################
def buildMaxHeap(array):
    lenth = len(array)
    for i in range(lenth//2,-1,-1):
        heapify(array,i)
def heapify(array,i):
    left = 2*i+1
    right = 2*i+2
    largest = i
    if left<lenth and array[left]>array[largest]:
        largest = left
    if right<lenth and array[right]>array[largest]:
        largest = right
    if largest != i:
        temp = array[i]
        array[i] = array[largest]
        array[largest] = temp
def HeapSort(array):
    lenth = len(array)
    buildMaxHeap(array)
    for i in range(len(array)-1,0,-1):
        temp = array[i]
        array[i] = array[0]
        array[0] = temp
        lenth += -1
        heapify(array,0)
    return array

 

  ##############################
 #        8、计数排序          #
#############################
def CountingSort(array,maxValue):
    bucket = [0]*(maxValue+1)
    sortedIndex = 0
    arrLen = len(array)
    bucketLen = maxValue+1
    for i in range(0,arrLen):
        bucket[array[i]] += 1
    for j in range(0,bucketLen):
        while(bucket[j]>0):
            array[sortedIndex] = j
            sortedIndex += 1
            bucket[j] += -1
             
             
    return array

 

 

  ##############################
 #         9、桶排序           #
#############################
def BuckerSort(array,bucketSize):
    if len(array) == 0:
        return array
    minValue = array[0]
    maxValue = array[0]
    for i in range(1,len(array)):
        if array[i]<minValue:
            minValue = array[i]
        if array[i]>maxValue:
            maxValue = array[i]
            
    DEFAULT_BUCKET_SIZE = 5
    bucketSize = bucketSize or DEFAULT_BUCKET_SIZE
    bucketCount = ((maxValue-minValue)//bucketSize)+1
    buckets = []
    for i in range(0,len(buckets)):
        buckets[i] = []
    for i in range(0,len(array)):
        buckets[(array[i]-minValue)//bucketSize].append(array[i])
    array = []
    for i in range(0,len(buckets)):
        InsertionSort(buckets[i])
        for j in range(0,len(buckets[i])):
            array.append(buckets[i][j])
            
            
    return array

 

  ##############################
 #       10、基数排序        #
#############################
def RadixSort(array,maxDigit):
    counter = [0]*10
    mod = 10
    dev = 1
    for i in range(0,maxDigit):
        for j in range(0,len(array)):
            bucket = int((array[j] % mod) / dev)#求基数
            
            counter[bucket] = []
            counter[bucket].append(array[j])
        dev *= 10
        mod *= 10
    pos = 0
    for j in range(0,len(counter)):
        value = None
        if counter[j] is not None:
            while(len(counter[j]) != 0):
                value = counter[j].pop(0)
                array[pos] = value
                pos += 1
                
                
    return array