[LeetCode]628. Maximum Product of Three Numbers

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题目

Given an integer array, find three numbers whose product is maximum and output the maximum product.

Example 1:

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Input: [1,2,3]
Output: 6

Example 2:

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Input: [1,2,3,4]
Output: 24

Note:

  1. The length of the given array will be in range [3,104] and all elements are in the range [-1000, 1000].
  2. Multiplication of any three numbers in the input won’t exceed the range of 32-bit signed integer.

难度

Easy

方法

注意有负数的情况。对nums排序，取max(nums[-3] * nums[-2] * nums[-1], nums[0] * nums[1] * nums[-1])

python代码

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class Solution(object):
    def maximumProduct(self, nums):
        """
        :type nums: List[int]
        :rtype: int
        """
        nums = sorted(nums)
        return max(nums[-3] * nums[-2] * nums[-1], nums[0] * nums[1] * nums[-1])

assert Solution().maximumProduct([1,2,3,4]) == 24
assert Solution().maximumProduct([-4,-3,-2,-1,60]) == 720