Product of Array Except Self

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].

Follow up:
Could you solve it with constant space complexity? (Note: The output array does not count as extra space for the purpose of space complexity analysis.)

Runtime: 64ms

 1 class Solution {
 2 public:
 3     vector<int> productExceptSelf(vector<int>& nums) {
 4         vector<int> result(nums.size(), 1);
 5         
 6         for(int i = 1; i < nums.size(); i++)
 7             result[i] = nums[i - 1] * result[i - 1]; 
 8         
 9         int right = 1;
10         for(int i = nums.size() - 2; i >= 0; i--){
11             right *= nums[i + 1];
12             result[i] = right * result[i];
13         }
14         
15         return result;
16     }
17 };
原文地址:https://www.cnblogs.com/amazingzoe/p/4799833.html