Java Bitmap Flip flipBitmapRange(long[] bitmap, int start, int end)

Description

flip bits at start, start+1,..., end-1

License

Apache License

Parameter

Parameter	Description
bitmap	array of words to be modified
start	first index to be modified (inclusive)
end	last index to be modified (exclusive)

Declaration

public static void flipBitmapRange(long[] bitmap, int start, int end) 

Method Source Code

//package com.java2s;
/*/*from   w  w w . ja  v a2s  .  c  o  m*/
 * (c) the authors Licensed under the Apache License, Version 2.0.
 */

public class Main {
    /**
     * flip bits at start, start+1,..., end-1
     *
     * @param bitmap array of words to be modified
     * @param start first index to be modified (inclusive)
     * @param end last index to be modified (exclusive)
     */
    public static void flipBitmapRange(long[] bitmap, int start, int end) {
        if (start == end) {
            return;
        }
        int firstword = start / 64;
        int endword = (end - 1) / 64;
        bitmap[firstword] ^= ~(~0L << start);
        for (int i = firstword; i < endword; i++) {
            bitmap[i] = ~bitmap[i];
        }
        bitmap[endword] ^= ~0L >>> -end;
    }
}