logAllSubs.js

// let str = 'abc'


// const logSub = s => {
//   let res = []
//   for (let i =0; i<s.length; i++) {
//     for( let j=i+1; j<=s.length;j++) {
//       res.push(str.slice(i,j))
//     }
//   }
//   return res
// }
// console.log(
//   logSub(str)
// )

const log = s => {
  let res = []
  const iter = (temp, left) => {
    for (let i=0; i<left.length;i++) {
      iter(temp+left[i], [...left.slice(0,i), ...left.slice(i+1)])
    }
    res.push(temp)
  }
  iter('', s)
  return res
}



console.log(log(['a','b','c']))
console.log(log(['a','b']))

This algorithm returns all the combinations of an array