【Python】排序你学废了吗，茴香豆有四种写法，排序有十种写法

怼烎@ 2024-03-24 12:17 13阅读 0赞

1.  冒泡排序

def bubble_sort(arr):
        n = len(arr)
        for i in range(n):
            for j in range(n-i-1):
                if arr[j] > arr[j+1]:
                    arr[j], arr[j+1] = arr[j+1], arr[j]
        return arr

1.  插入排序

def insertion_sort(arr):
        n = len(arr)
        for i in range(1, n):
            key = arr[i]
            j = i - 1
            while j >= 0 and key < arr[j]:
                arr[j+1] = arr[j]
                j -= 1
            arr[j+1] = key
        return arr

1.  选择排序

def selection_sort(arr):
        n = len(arr)
        for i in range(n-1):
            min_idx = i
            for j in range(i+1, n):
                if arr[j] < arr[min_idx]:
                    min_idx = j
            arr[i], arr[min_idx] = arr[min_idx], arr[i]
        return arr

1.  快速排序

def quick_sort(arr):
        if len(arr) <= 1:
            return arr
        pivot = arr[len(arr) // 2]
        left = [x for x in arr if x < pivot]
        middle = [x for x in arr if x == pivot]
        right = [x for x in arr if x > pivot]
        return quick_sort(left) + middle + quick_sort(right)

1.  归并排序

def merge_sort(arr):
        if len(arr) <= 1:
            return arr
        mid = len(arr) // 2
        left = arr[:mid]
        right = arr[mid:]
        left = merge_sort(left)
        right = merge_sort(right)
        return merge(left, right)
        
    def merge(left, right):
        result = []
        i = j = 0
        while i < len(left) and j < len(right):
            if left[i] < right[j]:
                result.append(left[i])
                i += 1
            else:
                result.append(right[j])
                j += 1
        result += left[i:]
        result += right[j:]
        return result

1.  堆排序

def heapify(arr, n, i):
        largest = i
        l = 2 * i + 1
        r = 2 * i + 2
        if l < n and arr[l] > arr[largest]:
            largest = l
        if r < n and arr[r] > arr[largest]:
            largest = r
        if largest != i:
            arr[i], arr[largest] = arr[largest], arr[i]
            heapify(arr, n, largest)
            
    def heap_sort(arr):
        n = len(arr)
        for i in range(n // 2 - 1, -1, -1):
            heapify(arr, n, i)
        for i in range(n-1, 0, -1):
            arr[i], arr[0] = arr[0], arr[i]
            heapify(arr, i, 0)
        return arr

1.  希尔排序

def shell_sort(arr):
        n = len(arr)
        gap = n // 2
        while gap > 0:
            for i in range(gap, n):
                temp = arr[i]
                j = i
                while j >= gap and arr[j-gap] > temp:
                    arr[j] = arr[j-gap]
                    j -= gap
                arr[j] = temp
            gap //= 2
        return arr

1.  计数排序

def counting_sort(arr):
        n = len(arr)
        max_val = max(arr) + 1
        count = [0] * max_val
        for i in range(n):
            count[arr[i]] += 1
        for i in range(1, max_val):
            count[i] += count[i-1]
        output = [0] * n
        for i in range(n-1, -1, -1):
            output[count[arr[i]]-1] = arr[i]
            count[arr[i]] -= 1
        return output

1.  桶排序

def bucket_sort(arr):
        n = len(arr)
        max_val = max(arr) + 1
        bucket = [[] for _ in range(n)]
        for i in range(n):
            index = arr[i] * n // max_val
            bucket[index].append(arr[i])
        for i in range(n):
            bucket[i].sort()
        output = []
        for i in range(n):
            output += bucket[i]
        return output

1.  基数排序

def radix_sort(arr):
        max_val = max(arr)
        exp = 1
        while max_val // exp > 0:
            arr = counting_sort_by_digit(arr, exp)
            exp *= 10
        return arr
    
    def counting_sort_by_digit(arr, exp):
        n = len(arr)
        max_val = max(arr) // exp
        count = [0] * 10
        for i in range(n):
            index = (arr[i] // exp) % 10
            count[index] += 1
        for i in range(1, 10):
            count[i] += count[i-1]
        output = [0] * n
        for i in range(n-1, -1, -1):
            index = (arr[i] // exp) % 10
            output[count[index]-1] = arr[i]
            count[index] -= 1
        return output

茴香豆有四种写法，排序有十种写法，你学废了嘛~~~