There are two sorted arrays nums1 and nums2 of size m and n respectively.
Find the median of the two sorted arrays. The overall run time complexity should be O(log (m+n)).
You may assume nums1 and nums2 cannot be both empty.
Example 1:
nums1 = [1, 3] nums2 = [2] The median is 2.0
Example 2:
nums1 = [1, 2] nums2 = [3, 4]
"""
第一次：思路是将num2中的数据向num1中插，分三种情况：①有一个为空或者num2中的数据均小于num1中的数据；②num2中的数据均大于num1中的数据；③num1与num2中的数据有大有小。返回情况分两种：num1中的数据为偶数个，返回中间两个的平均数，num1中的数据为奇数个，返回中间一个数。
"""
class Solution(object):
def findMedianSortedArrays(self, nums1, nums2):
"""
:type nums1: List[int]
:type nums2: List[int]
:rtype: float
"""
m, n = len(nums1), len(nums2)
x = m + n
midden = [x // 2, x // 2 -1] if not x % 2 else [x // 2]
if m == 0 or n == 0 or nums2[n - 1] <= nums1[0]:
nums2.extend(nums1)
nums1 = nums2
elif nums2[0] >= nums1[m - 1]:
nums1.extend(nums2)
else:
for num in nums2:
left = 0
right = len(nums1) - 1
while left < right:
mid = (left + right) // 2
if num < nums1[mid]:
if num > nums1[mid - 1]:
nums1.insert(mid, num)
break
else:
left, right = 0, mid - 1
continue
if num > nums1[mid]:
if num < nums1[mid + 1]:
nums1.insert(mid + 1, num)
break
else:
left, right = mid + 1, len(nums1) - 1
continue
if num <= nums1[0]:
nums1.insert(0, num)
continueif num >= nums1[-1]:
nums1.append(num)
continuereturn nums1[midden[0]] if len(midden) == 1 else (nums1[midden[0]] + nums1[midden[1]]) / 2.0
"""
Time Limit Exceeded
"""
"""
第二次：对nums1和nums2使用归并排序，排序结果保存到tmp中
"""
class Solution(object):
def findMedianSortedArrays(self, nums1, nums2):
"""
:type nums1: List[int]
:type nums2: List[int]
:rtype: float
"""
tmp = []
if len(nums1) == 0 or len(nums2) == 0 or nums1[-1] < nums2[0]:
nums1.extend(nums2)
tmp = nums1elif nums1[0] > nums2[-1]:
nums2.extend(nums1)
tmp = nums2
else:
i, j = 0, 0
while i < len(nums1) or j < len(nums2):
if i == len(nums1):
tmp.extend(nums2[j:])
break
elif j == len(nums2):
tmp.extend(nums1[i:])
break
else:
if nums1[i] < nums2[j]:
tmp.append(nums1[i])
i += 1
else:
tmp.append(nums2[j])
j += 1
print(tmp)
l = len(tmp)
return tmp[l//2] if l % 2 else (tmp[l//2] + tmp[(l//2)-1]) / 2.0"""
Runtime: 192 ms, faster than 7.41% of Python online submissions forMedian of Two Sorted Arrays.
Memory Usage: 12 MB, less than 5.48% of Python online submissions forMedian of Two Sorted Arrays.
"""