Given a bitstring generate all bitstring with n flipped bits
$begingroup$
For an algorithm I need to be able to iterate over all bit strings where $k$ bits are flipped given a bit string with length $n$ and $n geq k$. For instance let's say I have the bit string $1001$ and I want to have all bit strings with $2$ bits flipped. That should result in the following bit strings:
1010
1100
1110
0000
0011
0101
So given a bit string of length $n$ and where $k$ bits will be flipped the result will be $binom{n}{k}$ bit strings. Is there an efficient way to generate all of them? The bit strings I have as input are just unsigned integers so I can use bit twiddling!
algorithms combinatorics bit-manipulation
$endgroup$
add a comment |
$begingroup$
For an algorithm I need to be able to iterate over all bit strings where $k$ bits are flipped given a bit string with length $n$ and $n geq k$. For instance let's say I have the bit string $1001$ and I want to have all bit strings with $2$ bits flipped. That should result in the following bit strings:
1010
1100
1110
0000
0011
0101
So given a bit string of length $n$ and where $k$ bits will be flipped the result will be $binom{n}{k}$ bit strings. Is there an efficient way to generate all of them? The bit strings I have as input are just unsigned integers so I can use bit twiddling!
algorithms combinatorics bit-manipulation
$endgroup$
add a comment |
$begingroup$
For an algorithm I need to be able to iterate over all bit strings where $k$ bits are flipped given a bit string with length $n$ and $n geq k$. For instance let's say I have the bit string $1001$ and I want to have all bit strings with $2$ bits flipped. That should result in the following bit strings:
1010
1100
1110
0000
0011
0101
So given a bit string of length $n$ and where $k$ bits will be flipped the result will be $binom{n}{k}$ bit strings. Is there an efficient way to generate all of them? The bit strings I have as input are just unsigned integers so I can use bit twiddling!
algorithms combinatorics bit-manipulation
$endgroup$
For an algorithm I need to be able to iterate over all bit strings where $k$ bits are flipped given a bit string with length $n$ and $n geq k$. For instance let's say I have the bit string $1001$ and I want to have all bit strings with $2$ bits flipped. That should result in the following bit strings:
1010
1100
1110
0000
0011
0101
So given a bit string of length $n$ and where $k$ bits will be flipped the result will be $binom{n}{k}$ bit strings. Is there an efficient way to generate all of them? The bit strings I have as input are just unsigned integers so I can use bit twiddling!
algorithms combinatorics bit-manipulation
algorithms combinatorics bit-manipulation
asked Dec 27 '18 at 12:00
John SmithJohn Smith
1184
1184
add a comment |
add a comment |
1 Answer
1
active
oldest
votes
$begingroup$
Let your initial bit string be x
.
For all numbers b
with k
bits set (i.e. where k
bits are 1), output x xor b
.
Finding all numbers with k
bits set is described elsewhere, for example here
$endgroup$
add a comment |
Your Answer
StackExchange.ifUsing("editor", function () {
return StackExchange.using("mathjaxEditing", function () {
StackExchange.MarkdownEditor.creationCallbacks.add(function (editor, postfix) {
StackExchange.mathjaxEditing.prepareWmdForMathJax(editor, postfix, [["$", "$"], ["\\(","\\)"]]);
});
});
}, "mathjax-editing");
StackExchange.ready(function() {
var channelOptions = {
tags: "".split(" "),
id: "419"
};
initTagRenderer("".split(" "), "".split(" "), channelOptions);
StackExchange.using("externalEditor", function() {
// Have to fire editor after snippets, if snippets enabled
if (StackExchange.settings.snippets.snippetsEnabled) {
StackExchange.using("snippets", function() {
createEditor();
});
}
else {
createEditor();
}
});
function createEditor() {
StackExchange.prepareEditor({
heartbeatType: 'answer',
autoActivateHeartbeat: false,
convertImagesToLinks: false,
noModals: true,
showLowRepImageUploadWarning: true,
reputationToPostImages: null,
bindNavPrevention: true,
postfix: "",
imageUploader: {
brandingHtml: "Powered by u003ca class="icon-imgur-white" href="https://imgur.com/"u003eu003c/au003e",
contentPolicyHtml: "User contributions licensed under u003ca href="https://creativecommons.org/licenses/by-sa/3.0/"u003ecc by-sa 3.0 with attribution requiredu003c/au003e u003ca href="https://stackoverflow.com/legal/content-policy"u003e(content policy)u003c/au003e",
allowUrls: true
},
onDemand: true,
discardSelector: ".discard-answer"
,immediatelyShowMarkdownHelp:true
});
}
});
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
StackExchange.ready(
function () {
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fcs.stackexchange.com%2fquestions%2f102086%2fgiven-a-bitstring-generate-all-bitstring-with-n-flipped-bits%23new-answer', 'question_page');
}
);
Post as a guest
Required, but never shown
1 Answer
1
active
oldest
votes
1 Answer
1
active
oldest
votes
active
oldest
votes
active
oldest
votes
$begingroup$
Let your initial bit string be x
.
For all numbers b
with k
bits set (i.e. where k
bits are 1), output x xor b
.
Finding all numbers with k
bits set is described elsewhere, for example here
$endgroup$
add a comment |
$begingroup$
Let your initial bit string be x
.
For all numbers b
with k
bits set (i.e. where k
bits are 1), output x xor b
.
Finding all numbers with k
bits set is described elsewhere, for example here
$endgroup$
add a comment |
$begingroup$
Let your initial bit string be x
.
For all numbers b
with k
bits set (i.e. where k
bits are 1), output x xor b
.
Finding all numbers with k
bits set is described elsewhere, for example here
$endgroup$
Let your initial bit string be x
.
For all numbers b
with k
bits set (i.e. where k
bits are 1), output x xor b
.
Finding all numbers with k
bits set is described elsewhere, for example here
answered Dec 27 '18 at 12:38
Albert HendriksAlbert Hendriks
1,391529
1,391529
add a comment |
add a comment |
Thanks for contributing an answer to Computer Science Stack Exchange!
- Please be sure to answer the question. Provide details and share your research!
But avoid …
- Asking for help, clarification, or responding to other answers.
- Making statements based on opinion; back them up with references or personal experience.
Use MathJax to format equations. MathJax reference.
To learn more, see our tips on writing great answers.
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
StackExchange.ready(
function () {
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fcs.stackexchange.com%2fquestions%2f102086%2fgiven-a-bitstring-generate-all-bitstring-with-n-flipped-bits%23new-answer', 'question_page');
}
);
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown