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.)
public class Solution { public int[] productExceptSelf(int[] nums) { int[] a = new int[nums.length]; int[] b = new int[nums.length]; int[] res = new int[nums.length]; a[0] = 1; for(int i=1;i<nums.length;i++) { a[i] = a[i-1]*nums[i-1]; } b[nums.length-1] = 1; for(int j=nums.length-2;j>=0;j--) { b[j] = b[j+1]*nums[j+1]; } for(int s=0;s<nums.length;s++) { res[s] = a[s]*b[s]; } return res; } }
原文：http://www.cnblogs.com/hygeia/p/5085331.html