Note: 순열 & 조합

[YimJiYoung]

function getAllSubsets(array) {
    const subsets = [[]];
    
    for (const el of array) {
        const last = subsets.length-1;
        for (let i = 0; i <= last; i++) { // 기존 subset 배열에 자신을 추가한 새로운 배열 만들어 push
            subsets.push( [...subsets[i], el] ); 
        }
    }
    
    return subsets;
}

Here is an example for [1, 2, 3]

• Start with an empty subset: []

• Create new subsets by adding "1" to each existing subset. It will be:[] [1]

• Create new subsets by adding "2" to each existing subset. It will be:[], [1] [2], [1, 2]

• Create new subsets by adding "3" to each existing subset. It will be: [], [1], [2], [1, 2] [3], [1, 3], [2, 3], [1, 2, 3]

참고 : https://stackoverflow.com/questions/42773836/how-to-find-all-subsets-of-a-set-in-javascript

[YimJiYoung]

조합

const permutator = (inputArr) => {
  let result = [];

  const permute = (arr, m = []) => {
    if (arr.length === 0) {
      result.push(m)
    } else {
      for (let i = 0; i < arr.length; i++) {
        let curr = arr.slice();
        let next = curr.splice(i, 1); // 하나씩 선택
        permute(curr, m.concat(next))
     }
   }
 }

 permute(inputArr)

 return result;
}

참고 : https://stackoverflow.com/questions/9960908/permutations-in-javascript?page=1&tab=votes