maximum product of three numbers

Maximum Product of Three Numbers

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.

代码一(78ms),排序耗费了不少时间,再想想不排序的办法:

class Solution {
public:
    int maximumProduct(vector<int>& nums) {
        sort(nums.begin(), nums.end());
        int s = nums.size() - 1;
        if (nums[0] < 0 && nums[1] < 0) {
            return max(nums[0] * nums[1] * nums[s], nums[s] * nums[s - 1] * nums[s - 2]);
        }

        return nums[s] * nums[s - 1] * nums[s - 2];
    }
};