1 # -*- coding: utf-8 -*- 2 import math 3 4 def merge(l1, l2): 5 list_merge = [] 6 i = j = 0 7 while i < len(l1) and j < len(l2): 8 if l1[i] < l2[j]: 9 list_merge.append(l1[i]) 10 i += 1 11 else: 12 list_merge.append(l2[j]) 13 j += 1 14 if i == len(l1): 15 while j < len(l2): 16 list_merge.append(l2[j]) 17 j += 1 18 else: 19 while i < len(l1): 20 list_merge.append(l1[i]) 21 i += 1 22 return list_merge 23 24 def problem_9_3_8(list1, list2, l1, r1, l2, r2): 25 if l1 == r1: 26 if list1[l1] < list2[l2]: 27 return list1[l1], list2[l2] 28 else: 29 return list2[l2], list1[l1] 30 31 if (r1 - l1 + 1) % 2: # 每个数组中元素是奇数，分别只有一个中位数 32 l1_m = (r1 + l1) // 2 33 l2_m = (r2 + l2) // 2 34 if list1[l1_m] < list2[l2_m]: 35 return problem_9_3_8(list1, list2, l1_m, r1, l2, l2_m) 36 elif list1[l1_m] > list2[l2_m]: 37 return problem_9_3_8(list1, list2, l1, l1_m, l2_m, r2) 38 else: 39 return list1[l1_m], list2[l2_m] 40 else : # 每个数组中元素是偶数，则分别有两个中位数 此时有C(3,1)+C(3,2) = 6种情况 41 l1_m1 = math.floor((r1 + l1) / 2) 42 l1_m2 = math.ceil((r1 + l1) / 2) 43 44 l2_m1 = math.floor((r2 + l2) / 2) 45 l2_m2 = math.ceil((r2 + l2) / 2) 46 47 if (list1[l1_m2] <= list2[l2_m1]) : # L1下 <= L1上 <= L2下 <= L2上 48 return problem_9_3_8(list1, list2, l1_m2, r1, l2, l2_m1) 49 elif list2[l2_m2] <= list1[l1_m1]: # L2下 <= L2上 <= L1下 <= L1上 50 return problem_9_3_8(list1, list2, l1, l1_m1, l2_m2, r2) 51 elif (list1[l1_m1] <= list2[l2_m1]) and (list2[l2_m1] <= list1[l1_m2]) and (list1[l1_m2] <= list2[l2_m2]): # L1下 <= L2下 <= L1上 <= L2上 52 return list2[l2_m1], list1[l1_m2] 53 elif (list2[l2_m1] <= list1[l1_m1]) and (list1[l1_m1] <= list2[l2_m2]) and (list2[l2_m2] <= list1[l1_m2]): # L2下 <= L1下 <= L2上 <= L1上 54 return list1[l1_m1], list2[l2_m2] 55 elif (list2[l2_m1] <= list1[l1_m1]) and (list1[l1_m2] <= list2[l2_m2]): # L2下 <= L1下 <= L1上 <= L2上 56 return list1[l1_m1], list1[l1_m2] 57 else: # (list1[l1_m1] <= list2[l2_m1]) and (list2[l2_m2] <= list1[l1_m2]): # L1下 <= L2下 <= L2上 <= L1上 58 return list2[l2_m1], list2[l2_m2] 59 60 61 list1 = [i*11 for i in range(300)] 62 list2 = [i*7 for i in range(300)] 63 64 list4 = merge(list1, list2) 65 print(list4) 66 print(list4[math.floor((len(list4)-1)/2)], list4[math.ceil((len(list4)-1)/2)]) 67 68 m1,m2 = problem_9_3_8(list1, list2, 0, len(list1)-1, 0, len(list2)-1) 69 print(m1,m2)