bitwise-and

问题 Actually i would like to compare some values in a table with an array and output the key with has equal value of the array. Problem is: the values in the database are bitwise if i am right. Not sure if it is the right explanation in english. Example: and here some example values form the table 1,65,2081,2145,18497,32769 65 contains 64 which is "UR_LEAD" and 1 which is "UR_SWP" Here the array which i would like to compare with: $userrights_array = array( "UR_SWP" => 1, "UR_BUHA" => 2, "UR_AZ"

问题 Given a very large array of integers in which element can go upto 10^9 how do I find a pair with maximum AND value. My current approach is I calculate all possible pairs and traverse through it and find maximum, however it is very slow. Any other approach? 回答1: As long as you can find at least two numbers with the same most significant bit set, the solution will involve two of them. Next, discard all other elements and remove everything left of this MSB for the numbers not discarded and solve

来源： https://stackoverflow.com/questions/22593822/doing-a-bitwise-operation-on-bytes

来源： https://stackoverflow.com/questions/22593822/doing-a-bitwise-operation-on-bytes

来源： https://stackoverflow.com/questions/22593822/doing-a-bitwise-operation-on-bytes

来源： https://stackoverflow.com/questions/22593822/doing-a-bitwise-operation-on-bytes

来源： https://stackoverflow.com/questions/26359068/mask-and-extract-bits-in-c

问题 I am trying to do assignment: "Find the number of bits in an unsigned integer data type without using the sizeof() function." And my design is to convert the integer to bits and then to count them. For ex: 10 is 1010 and 5 is 101 Converting integer to a bit representation shows something like this: do { Vec.push_back( x & 1 ) } while ( x >>= 1 ); I don't want to just copy paste stuff. When I use F-10 I see what (x & 1) is doing but I don't know it is name or how it does its job(compare

问题 does anyone know how to use bitwise AND (&) as criteria for a JPA NamedQuery without having to use a @NamedNativeQuery? I'm storing status bits in a field. I'm using the following defs for an entity of a view: @NamedQueries({ @NamedQuery(name="ViewProductsList.findAll", query="SELECT v FROM ViewProductsList v"), @NamedQuery(name="ViewProductsList.findFeatured", query="SELECT v FROM ViewProductsList v WHERE v.statusId & 16"), @NamedQuery(name="ViewProductsList.findBySubcategory", query="SELECT

问题 does anyone know how to use bitwise AND (&) as criteria for a JPA NamedQuery without having to use a @NamedNativeQuery? I'm storing status bits in a field. I'm using the following defs for an entity of a view: @NamedQueries({ @NamedQuery(name="ViewProductsList.findAll", query="SELECT v FROM ViewProductsList v"), @NamedQuery(name="ViewProductsList.findFeatured", query="SELECT v FROM ViewProductsList v WHERE v.statusId & 16"), @NamedQuery(name="ViewProductsList.findBySubcategory", query="SELECT