Merge pull request #403 from rubiin/master

Added createPermutation function

Author: ruppysuppy

String/createPurmutations.js

@@ -0,0 +1,37 @@
+/*
+a permutation of a set is, loosely speaking, an arrangement of its members into a sequence or linear order, or if the set is already ordered, a rearrangement of its elements.
+The word "permutation" also refers to the act or process of changing the linear order of an ordered set
+More at : https://en.wikipedia.org/wiki/Permutation
+*/
+
+const createPermutations = (str) => {
+// convert string to array
+  const arr = str.split('')
+
+  // get array length
+  const strLen = arr.length
+  // this will hold all the permutations
+  const perms = []
+  let rest
+  let picked
+  let restPerms
+  let next
+
+  // if strLen is zero, return the same string
+  if (strLen === 0) { return [str] }
+  // loop to the length to get all permutations
+  for (let i = 0; i < strLen; i++) {
+    rest = Object.create(arr)
+    picked = rest.splice(i, 1)
+
+    restPerms = createPermutations(rest.join(''))
+
+    for (let j = 0, jLen = restPerms.length; j < jLen; j++) {
+      next = picked.concat(restPerms[j])
+      perms.push(next.join(''))
+    }
+  }
+  return perms
+}
+
+console.log(createPermutations('abc')) // should print ["abc", "acb", "bac", "bca", "cab", "cba"]