leetcode349之实现求解两个数组的交集

##四种方式求解：

# 给定两个数组，编写一个函数来计算它们的交集


def intersection(nums1, nums2):
    '''
    给定两个数组，编写一个函数来计算它们的交集
    :param nums1: list
    :param nums2: list
    :return:
    '''
    nums1 = set(nums1)
    nums2 = set(nums2)
    temp_array = []
    for i in nums1:
        if i in nums2:
            temp_array.append(i)

    return temp_array


print('_________测试intersection()________________')
nums1 = [1, 2, 3, 2, 4, 2] 24 nums2 = [2, 3, 2, 1, 2, 4, 5, 2]
temp_array = intersection(nums1, nums2)
print("temp_array=", temp_array)


def intersection2(nums1, nums2):
    '''
    方法二
    :param nums1:
    :param nums2:
    :return:
    '''
    temp_array = []
    for i in nums1:
        if i in nums2:
            if i not in temp_array:
                temp_array.append(i)
    return temp_array


print('-----------测试intersection2()-------------')
array = intersection2(nums1, nums2)
print('array=', array)


def binarySearch(nums, target):
    '''
    二分查找法
    :param nums:
    :param target:
    :return:
    '''
    left = 0
    right = len(nums) - 1
    while left <= right:
        mid = left + (right - left) // 2
        if nums[mid] == target:
            return True
        elif nums[mid] < target:
            left = mid + 1
        else:
            right = mid - 1

    return False


def intersection3(nums1, nums2):
    '''

    :param nums1:
    :param nums2:
    :return:
    '''
    return set(nums1) & set(nums2)


print('+++++++++测试intersection3()+++++++++++++')
array = intersection3(nums1, nums2)
print("array=", array)


def intersections4(nums1, nums2):
    '''

    :param nums1:
    :param nums2:
    :return:
    '''
    nums1 = sorted(nums1)
    array4 = []
    for i in nums2:
        if i not in array4:
            if binarySearch(nums1, i):
                array4.append(i)

    return array4


print("=================测试interSearch()===========")
array4 = intersections4(nums1, nums2)
print('array4=', array4)

输出：

_________测试intersection()________________
sorted nums1= [1, 2, 2, 2, 3, 4]
temp_array= [1, 2, 3, 4]
-----------测试intersection2()-------------
array= [1, 2, 3, 4]
+++++++++测试intersection3()+++++++++++++
array= {1, 2, 3, 4}
=================测试interSearch()===========
array4= [2, 3, 1, 4]