(Skill)238. 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].

public class Solution {  //左边的数乘积乘以右边的数乘积。
 public int[] productExceptSelf(int[] nums) {
        int[] res=new int[nums.length];
        res[0]=1;
        int acc=1;
        for(int i=1;i<nums.length;i++){
            res[i]=res[i-1]*nums[i-1];
        }
        for(int i=nums.length-1;i>=0;i--){
            res[i]*=acc;
            acc*=nums[i];
        }
        return res;
    }
}