how to find all permutations of an array with javascript
function getArrayMutations(arr, perms = [], len = arr.length) {
if (len === 1) perms.push(arr.slice(0))
for (let i = 0; i < len; i++) {
getArrayMutations(arr, perms, len - 1)
len % 2 // parity dependent adjacent elements swap
? [arr[0], arr[len - 1]] = [arr[len - 1], arr[0]]
: [arr[i], arr[len - 1]] = [arr[len - 1], arr[i]]
}
return perms
}how to get all permutations of an array
/* to be used something like this:
int [] toBePermuted = new int [] {1, 2, 3, 4};
ArrayList<int[]> a = heap(toBePermuted);
any mention of int [] can be replaced with any other Array of objects */
ArrayList<int []> heap(int [] input) {
ArrayList<int []> ret = new ArrayList<int []> ();
ret = generate(input.length, input, ret);
return ret;
}
ArrayList<int []> generate(int k, int [] a, ArrayList<int []> output) {
if (k == 1) {
output.add(a.clone());
} else {
output = generate(k-1, a, output);
for (int i=0; i<k-1; i++) {
if (k%2 == 0) {
int temp = a[i];
a[i] = a[k-1];
a[k-1] = temp;
} else {
int temp = a[0];
a[0] = a[k-1];
a[k-1] = temp;
}
generate(k-1, a, output);
}
}
return output;
}Copyright © 2021 Codeinu
Forgot your account's password or having trouble logging into your Account? Don't worry, we'll help you to get back your account. Enter your email address and we'll send you a recovery link to reset your password. If you are experiencing problems resetting your password contact us
