Matrix Time Limit: 3000MS Memory Limit: 65536K Total Submissions: 17880 Accepted: 6709 Description Given an N*N matrix A, whose elements are either 0 or 1. A[i, j] means the number in the i-th row and j-th column. Initially we have A[i, j] = 0 (1
一.& 按位与 如果两个相应的二进制位都为1,则该位的结果值为1,否则为0应用:(1)清零 若想对一个存储单元清零,即使其全部二进制位为0,只要找一个二进制数,其中各个位符合一下条件:原来的数中为1的位,新数中相应位为0.然后使二者进行&运算,即可达到清零目的. a 00101011 b 10010100 c 00000000 //c = a & b (2)取一个数中某些指定位 若有一个整数a(2byte),想要取其中的低字节,只需要将a与8个1按位与即可. a 00101100
先上jquery源码: grep: function( elems, callback, inv ) { var retVal, ret = [], i = 0, length = elems.length; inv = !!inv; // Go through the array, only saving the items // that pass the validator function for ( ; i < length; i++ ) { retVal = !!callback(
Reverse Words in a String 单词取反 whowhoha@outlook.com Question: Given an input string s, reverse the string word by word. For example, given s = "the sky is blue", return "blue is sky the". void reverseWords(string &s) { vector <
最近在项目中使用between取不同的区间值问题,由于区间跨度大,而且区间多,又是前端传过来的参数,所以使用in和exists比较麻烦.然后就考虑使用between.现将使用方法记录一下. 假如表有个字段param_key,参数区间值为:100-300.1000-1999.3050-5000. 首先是between的用法是:param_key between value1 and value2.如果是有多个between则是:param_key between 100 and 300 and p