leetcode349之实现求解两个数组的交集

##四种方式求解：

  1 # 给定两个数组，编写一个函数来计算它们的交集
  2 
  3 
  4 def intersection(nums1, nums2):
  5     '''
  6     给定两个数组，编写一个函数来计算它们的交集
  7     :param nums1: list
  8     :param nums2: list
  9     :return:
 10     '''
 11     nums1 = set(nums1)
 12     nums2 = set(nums2)
 13     temp_array = []
 14     for i in nums1:
 15         if i in nums2:
 16             temp_array.append(i)
 17 
 18     return temp_array
 19 
 20 
 21 print('_________测试intersection()________________')
 22 nums1 = [1, 2, 3, 2, 4, 2] 24 nums2 = [2, 3, 2, 1, 2, 4, 5, 2]
 25 temp_array = intersection(nums1, nums2)
 26 print("temp_array=", temp_array)
 27 
 28 
 29 def intersection2(nums1, nums2):
 30     '''
 31     方法二
 32     :param nums1:
 33     :param nums2:
 34     :return:
 35     '''
 36     temp_array = []
 37     for i in nums1:
 38         if i in nums2:
 39             if i not in temp_array:
 40                 temp_array.append(i)
 41     return temp_array
 42 
 43 
 44 print('-----------测试intersection2()-------------')
 45 array = intersection2(nums1, nums2)
 46 print('array=', array)
 47 
 48 
 49 def binarySearch(nums, target):
 50     '''
 51     二分查找法
 52     :param nums:
 53     :param target:
 54     :return:
 55     '''
 56     left = 0
 57     right = len(nums) - 1
 58     while left <= right:
 59         mid = left + (right - left) // 2
 60         if nums[mid] == target:
 61             return True
 62         elif nums[mid] < target:
 63             left = mid + 1
 64         else:
 65             right = mid - 1
 66 
 67     return False
 68 
 69 
 70 def intersection3(nums1, nums2):
 71     '''
 72 
 73     :param nums1:
 74     :param nums2:
 75     :return:
 76     '''
 77     return set(nums1) & set(nums2)
 78 
 79 
 80 print('+++++++++测试intersection3()+++++++++++++')
 81 array = intersection3(nums1, nums2)
 82 print("array=", array)
 83 
 84 
 85 def intersections4(nums1, nums2):
 86     '''
 87 
 88     :param nums1:
 89     :param nums2:
 90     :return:
 91     '''
 92     nums1 = sorted(nums1)
 93     array4 = []
 94     for i in nums2:
 95         if i not in array4:
 96             if binarySearch(nums1, i):
 97                 array4.append(i)
 98 
 99     return array4
100 
101 
102 print("=================测试interSearch()===========")
103 array4 = intersections4(nums1, nums2)
104 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]