zoukankan      html  css  js  c++  java
  • #leetcode#Product of Array Except Self

    Product of Array Except Self

     Total Accepted: 442 Total Submissions: 1138My Submissions

    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.)








    sdf


    前几天刚看facebook的面经出现这题, leetocde就加上了, 不能用除法, 则维护当前元素左边全部元素的乘积以及右边全部元素的乘积, 相乘得到 product of array except self !


    Because we cannot use division, so assume we have two integer arrays with the same length of nums, int[] leftProd = new int[nums.length]; int[] rightProd = new int[nums.length], we store the product of all the left elements in leftProd and the product of all the right elements in rightProd, then the product of leftProd[i] and rightProd[i] will be the value we want to put into the result. take the example of num[] = {2, 4, 3, 6}, thenleftProd will be {1, 2, 8, 24} , and rightProd will be {72, 18, 6, 1}.

    public class Solution {
        public int[] productExceptSelf(int[] nums) {
            if(nums == null)    
                return null;
            int[] res = new int[nums.length];
            for(int i = 0; i < nums.length; i++){
                if(i == 0)
                    res[i] = 1;
                else
                    res[i] = res[i - 1] * nums[i - 1];
            }
            int prod = 1;
            for(int i = nums.length - 1; i >= 0; i--){
                res[i] = res[i] * prod;
                prod *= nums[i];
            }
            return res;
        }
    }



  • 相关阅读:
    将博客搬至CSDN
    操作excel文件爬取nvd.nist数据
    windows下如何制作和应用数字签名证书 全流程
    python虚拟环境
    Linux系统中python默认版本为python2.7,修改为python3 项目上传码云
    删除github中某个文件夹
    国外的一些测试技术网站
    PYTHON读取EXCEL内容再转变成HTML添加到OUTLOOK中
    数据结构之顺序表概念篇
    Python内置类型性能分析
  • 原文地址:https://www.cnblogs.com/lcchuguo/p/5324116.html
Copyright © 2011-2022 走看看