C#解leetcode 238. Product of Array Except Self

时间:2023-03-09 13:08:12
C#解leetcode   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].

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.)

代码的思路是:给定一个数组a,求数组a的第i位置的除自身之外的元素的乘积,可以将先求出数组a的第1个位置到第i-1个位置的乘积,存到数组b中,在求出第i+1个元素到第n个元素的乘积

public class Solution {
public int[] ProductExceptSelf(int[] nums) {
int[] result=new int[nums.Length];
int left=,right=;
result[]=;
for(int i=;i<nums.Length;i++)
{
result[i]= result[i-]*nums[i-];
} for(int i=nums.Length-;i>=;i--)
{
result[i]*=right;
right*=nums[i];
} return result;
}
}