LeetCode 16. 3Sum Closest

原创于 2019-08-05 13:47:09 发布 · 163 阅读

0 ·

CC 4.0 BY-SA版权

解题报告专栏收录该内容

1423 篇文章

订阅专栏

本文介绍了一种算法，用于寻找三个数的组合，使它们的和最接近给定的目标数。通过枚举第一个数并使用双指针技术找到剩余两个数，实现了高效的解决方案。

question

find three numbers whose sum is closed to the target number.

algorithm

Enumerate the first number, then get two numbers whose sum is closed to the target number minus the first number.

code

class Solution:
    def threeSumClosest(self, nums: List[int], target: int) -> int:
        nums.sort()
        ans = nums[0] + nums[1] + nums[2]
        sNum = len(nums)
        for a in range(sNum):
            b = a+1
            c = sNum-1
            while b < c:
                threeSum = nums[a] + nums[b] + nums[c]
                if abs(threeSum - target) < abs(ans - target):
                    ans = threeSum
                if threeSum == target:
                    return target
                elif nums[a] + nums[b] + nums[c] < target:
                    b += 1
                else:
                    c -= 1
        
        return ans