bitvector

I am learning C/C++ programming & have encountered the usage of 'Bit arrays' or 'Bit Vectors'. Am not able to understand their purpose? here are my doubts - Are they used as boolean flags? Can one use int arrays instead? (more memory of course, but..) What's this concept of Bit-Masking? If bit-masking is simple bit operations to get an appropriate flag, how do one program for them? is it not difficult to do this operation in head to see what the flag would be, as apposed to decimal numbers? I am looking for applications, so that I can understand better. for Eg - Q. You are given a file

I am confused about how a bit vector would work to do this (not too familiar with bit vectors). Here is the code given. Could someone please walk me through this? public static boolean isUniqueChars(String str) { int checker = 0; for (int i = 0; i < str.length(); ++i) { int val = str.charAt(i) - 'a'; if ((checker & (1 << val)) > 0) return false; checker |= (1 << val); } return true; } Particularly, what is the checker doing? int checker is used here as a storage for bits. Every bit in integer value can be treated as a flag, so eventually int is an array of bits (flag). Each bit in your code

In an assignment I am currently working on we need to work with bit vectors, but I am very unsure of how to do this in Python. They should be able to be from 4 bits to 20 bits. I have never worked with bit vector before, but I guess that one would one create arrays of unsigned bytes that you manipulated using the usual AND/OR/XOR operations. The important restriction here is: I cannot rely on any libraries other than those supplied with standard Python. I think I know how I would do this in C using arrays of 8 bit unsigned bytes: e.g. to turn the 18th bit of a zeroed array into a one, I would