leetcode之3Sum Closest

class Solution(object):
def threeSumClosest(self, nums, target):
"""
:type nums: List[int]
:type target: int
:rtype: int
"""
def threeSum(nums, sum1):
nums=sorted(nums)
n=len(nums)
if n==0:
return 0
if n <= 3:
if sum(nums) == sum1:
return True
else:
return None
i=0
while i<n:
l,r=i+1,n-1
target=sum1 -nums[i]
while l<r:
if nums[l]+nums[r]==target:
return sum1
elif nums[l]+nums[r] < target:
l+=1
else:
r-=1
i = i + 1
else:
return None
for i in range(10000):
if threeSum(nums, target + i) != None:
return target + i
if threeSum(nums, target - i) != None:
return target - i