Lintcode 65. Median of two Sorted Arrays (Python) (Hard)
阿新 • • 發佈:2018-12-12
Median of two Sorted Arrays
Description:
There are two sorted arrays A and B of size m and n respectively. Find the median of the two sorted arrays.
Example Given A=[1,2,3,4,5,6] and B=[2,3,4,5], the median is 3.5.
Given A=[1,2,3] and B=[4,5], the median is 3.
Challenge The overall run time complexity should be O(log (m+n)).
Code:
class Solution:
"""
@param: A: An integer array
@param: B: An integer array
@return: a double whose format is *.5 or *.0
"""
def findMedianSortedArrays(self, A, B):
# write your code here
le = len(A)+len(B)
if le%2==0:
print('even')
print ('left', self.findK(A,B,int(le/2)))
print('right', self.findK(A,B,int(le/2)+1))
return (self.findK(A,B,int(le/2))+self.findK(A,B,int(le/2)+1))/2
else:
return self.findK(A,B,int(le/2)+1)
def findK(self, A, B, k):
la, lb = len(A), len(B)
halfk = int(k/2)
print('halfk', k, halfk)
if la<lb:
return self.findK(B, A, k)
if lb == 0:
return A[k-1]
if k==1:
return min(A[0], B[0])
ib = min(lb, halfk) if halfk!=0 else 1
ia = k-ib if k-ib!=0 else 1
print('ia,ib',ia,ib)
if B[ib-1]==A[ia-1]:
return B[ib-1]
if B[ib-1]<A[ia-1]:
if lb==ib:
return A[ia-1]
return self.findK(A[:ia], B[ib:], ia)
if B[ib-1]>A[ia-1]:
if la==ia:
return B[ib-1]
return self.findK(A[ia:], B[:ib], ib)