https://leetcode.com/problems/product-of-array-except-self/
Given an array nums of n integers where n > 1, return an array output such that output[i] is equal to the product of all the elements of nums except nums[i].
Example:
Input: [1,2,3,4] Output: [24,12,8,6]Note: Please solve it without division and in O(n).
Follow up:Could you solve it with constant space complexity? (The output array does notcount as extra space for the purpose of space complexity analysis.)
代码：
class Solution { public: vector<int> productExceptSelf(vector<int>& nums) { int n = nums.size(); int cnt = 0; vector<int> ans; for(int i = 0; i < n; i ++) { if(nums[i] == 0) cnt ++; } if(cnt == n) { for(int i = 0; i < n; i ++) ans.push_back(0); return ans; } int t = 1, tt = 1; for(int i = 0; i < n; i ++) { if(nums[i] != 0) tt *= nums[i]; t *= nums[i]; } for(int i = 0; i < n; i ++) { if(nums[i] == 0) { if(cnt == 1) ans.push_back(tt); else ans.push_back(0); } else ans.push_back(t / nums[i]); } return ans; } };
转载于:https://www.cnblogs.com/zlrrrr/p/10708455.html
