标签：
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.)
Solution:
1 vector<int> productExceptSelf(vector<int>& nums) 2 { 3 vector<int> va(nums.size(), 1); 4 vector<int> vb(nums.size(), 1); 5 for (int i = 1; i < nums.size(); i++) 6 va[i] = va[i - 1] * nums[i - 1]; // ret[i] = nums[i - 1] * ... * nums[0] 7 8 for (int i = nums.size() - 2; i >= 0; i--) 9 vb[i] = vb[i + 1] * nums[i + 1]; 10 11 for (int i = 0; i < nums.size(); i++) 12 va[i] = va[i] * vb[i]; 13 14 return va; 15 }
[leetcode] 238. Product of Array Except Self
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原文地址：http://www.cnblogs.com/ym65536/p/5456987.html
