Maximum Product of Three Numbers --三个数乘积最大

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

Example 1:

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

 

Example 2:

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.

 题意：求数组中三个数乘积最大；

 思路：一看到这题，应该想起来要排序，但要注意元素有正有负，有两种情况，正数的话最大的三个数相乘为最大，最小的两个负数和最大的正数相乘，求这两者的最大值；

class Solution {
    public int maximumProduct(int[] nums) {
        Arrays.sort(nums);
        int len = nums.length;
        int result = Math.max(nums[0] * nums[1] * nums[len- 1], nums[len - 1] * nums[len - 2] * nums[len - 3]);
        return result;
    }
}