added GeneratePermutations in Backtracking

Author: chiranjeev-thapliyal

Backtracking/GeneratePermutations.js

@@ -0,0 +1,33 @@
+/*
+ * Problem Statement: Generate all distinct permutations of a string/array (all permutations should be in sorted order);
+ *
+ * What is permutations?
+ * - Permutation means possible arrangements in a set (here it is string/array);
+ *
+ * Reference to know more about permutations:
+ * - https://www.britannica.com/science/permutation
+ *
+ */
+
+const swap = (arr, i, j) => {
+  const newArray = [...arr];
+
+  [newArray[i], newArray[j]] = [newArray[j], newArray[i]] // Swapping elements ES6 way
+
+  return newArray
+}
+
+const permutations = (arr, low, high) => {
+  if (low === high) {
+    console.log(arr.join(' '))
+    return
+  }
+  for (let i = low; i <= high; i++) {
+    arr = swap(arr, low, i)
+    permutations(arr, low + 1, high)
+  }
+}
+
+// Driver Code
+const input = [1, 2, 3]
+permutations(input, 0, input.length - 1)