题目:在一个数组中,除了两个数外,其余数都是两两成对出现,找出这两个数,要求时间复杂度O(n),空间复杂度O(1) 分析:这道题考察位操作:异或(^),按位与(&),移位操作(>>, <<)等,Java代码及注释如下: public static int[] findTwoSingleNum(int[] num) { int[] twoNums = new int[2]; int result = 0; for (int i = 0; i < num.length;
1.安装mkyaffsimage, mkyaffs2image命令(用来制作yaffs文件系统) 第一个命令针对Flash小页512B,第二个针对Flash大页2KB首先下载压缩文件 yaffs_source_util_larger_small_page_nand.tar.bz2安装mkyaffs2image命令为例: tar –xjf yaffs_source_util_larger_small_page_nand.tar.bz2 //解压出yaffs1和yaffs2 cd /Developm
个数: var str = 'aaafsdsaaasasasasaa'; var json = {}; for (var i = 0; i < str.length; i++) { if(!json[str.charAt(i)]){ json[str.charAt(i)] = 1; }else{ json[str.charAt(i)]++; } }; console.log(json); var iMax = 0; var iIndex = ''; for(var key in json){ a
A robot is located at the top-left corner of a m x n grid (marked 'Start' in the diagram below). The robot can only move either down or right at any point in time. The robot is trying to reach the bottom-right corner of the grid (marked 'Finish' in t
在求解线性方程组时,会遇到以下几种情形:定解方程组.不定方程组.超定方程组.奇异方程组. 首先以定解线性方程组为例: format rat 化成分数 format short >> A=[,;,] A = >> B=[;] B = >> X=A\B X = 34.4828 12.4138 >> format rat >> X X = / / >> /*+/* ans = / >> >> format long