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VistasHow do array permutation splitting by (n)
So I have array
const arr = [ 1, 4, 5, 8]
I want to get all possible combinations of this array splitted by (n) number for example
function getNPermutate(arr, n) {
}
getNPermutate(arr, 3) // [[1, 4, 5], [1, 4, 8], [4, 5, 8],[1, 5 ,8] ]
!array can be any length
I found the solution with simple permutation, but dont understand how do splitted permutation
function permute(nums) {
let result = [];
if (nums.length === 0) return [];
if (nums.length === 1) return [nums];
for (let i = 0; i < nums.length; i++) {
const currentNum = nums[i];
const remainingNums = nums.slice(0, i).concat(nums.slice(i + 1));
const remainingNumsPermuted = permute(remainingNums);
for (let j = 0; j < remainingNumsPermuted.length; j++) {
const permutedArray = [currentNum].concat(remainingNumsPermuted[j]);
result.push(permutedArray);
}
}
return result;
}
console.log(permute([1,2,3,4]))
·
Juan Pablo Isaza
2 Respuestas
Responde la pregunta0
You can try this one:
Script:
function test() {
var array = [1, 4, 5, 8];
console.log(getCombinations(array, 3))
}
function getCombinations(chars, len) {
var result = [];
var f = function(prefix, chars) {
for (var i = 0; i < chars.length; i++) {
var elem = [...prefix, chars[i]];
if(elem.length == len)
result.push(elem);
f(elem, chars.slice(i + 1));
}
}
f([], chars);
return result;
}
Output:
·
Juan Pablo Isaza
Denunciar
0
You could use a recursive generator:
function* iterPerms(arr, n, first=0) {
if (n > arr.length - first) return;
if (n === 0) return yield [];
for (const res of iterPerms(arr, n - 1, first + 1)) yield [arr[first], ...res];
yield* iterPerms(arr, n, first + 1);
}
const arr = [1, 4, 5, 8];
for (let perm of iterPerms(arr, 3)) console.log(...perm);To convert the generator to a normal function that returns a nested array, do:
const getNPermutate = (arr, n) => Array.from(iterPerms(arr, n));
·
Juan Pablo Isaza
Denunciar
Responde la pregunta