016 3sum closest
16. 3Sum Closest
题目: https://leetcode.com/problems/3sum-closest/
难度:
Medium
思路： 跟3 Sum一样，固定一个元素
用两个指针来循环
class Solution(object):
def threeSumClosest(self, nums, target):
"""
:type nums: List[int]
:rtype: List[List[int]]
"""
n, res, diff = len(nums), None, float('inf')
nums.sort()
for i in range(n):
if i > 0 and nums[i] == nums[i-1]:
continue
l, r = i+1, n-1
while l < r:
tmp = nums[i] + nums[l] + nums[r]
if tmp == target:
return target
elif tmp > target:
r -= 1
if abs(tmp-target) < diff:
diff = abs(tmp-target)
res = tmp
while l < r and nums[r] == nums[r+1]:
r -= 1
else:
l += 1
if abs(tmp-target) < diff:
diff = abs(tmp-target)
res = tmp
while l < r and nums[l] == nums[l-1]:
l += 1
return res
