leetcode Product of Array Except Self 生成除自己之外的数组

Given an array of n integers where n > 1, nums, return an array output such that output[i] is equal to the product of all the elements of nums except nums[i].

Solve it without division and in O(n).

For example, given [1,2,3,4], return [24,12,8,6].
题意：给定一个数组，在每个位置生成其他位置相乘得到的值。
思路：定义一个值记录0的个数，一个值记录除0外元素的乘积。
时间复杂度O（n），空间复杂度O（1）。

class Solution {
public:
    vector<int> productExceptSelf(vector<int>& nums) {
        int temp = 1, zeroCount = 0;
        for (auto ele : nums) {
            if (ele) temp *= ele;
            else zeroCount++;
        }
        if(zeroCount == 0) 
            for (int i = 0; i < nums.size(); ++i)
                nums[i] = temp / nums[i];
        else
            for (int i = 0; i < nums.size(); ++i) {            
                if (nums[i]) nums[i] = 0;
                else if (zeroCount == 1) nums[i] = temp;
                else nums[i] = 0;
            }
        return nums;
    }
};