# Find All the Well Ordered Permutations of a Given String.

Objective: Write an algorithm to Print All the Well Ordered Permutations of a Given String.

What is Well Ordered String: When all the alphabets in a string occur in the increasing order irrespective of Lower Case or Upper case.

http://www.careercup.com/question?id=6206517812396032

Example :

```"Sumit" - Not Well Ordered . 'u' occurred after 'S'.

"Now" - Well Ordered. N<o<W.

Input: Interview
Output:
[e, e, I, i, n, r, t, v, w]
[e, e, i, I, n, r, t, v, w]
[e, e, i, I, n, r, t, v, w]
[e, e, I, i, n, r, t, v, w]

```

Approach:

Code:

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 import java.util.Arrays; public class WellFormedStrings { // Logic: // 1. Get the input sequence // 2. Find out all the permutations of a String // 3. Before printing if the permutation is well formed. char[] A; public void wellFormedString(String S) { A = S.toCharArray(); permutation(A, 0); } public void permutation(char[] A, int left) { if (left == A.length) { if (isWellFormed(A)) { System.out.println(Arrays.toString(A)); } return; } for (int i = left; i < A.length; i++) { swap(i, left); permutation(A, left + 1); swap(i, left); // backtrack } } public void swap(int a, int b) { char temp = A[a]; A[a] = A[b]; A[b] = temp; } public boolean isWellFormed(char[] A) { boolean wellFormed = true; for (int i = 0; i < A.length – 1; i++) { if (Character.toLowerCase(A[i]) > Character.toLowerCase(A[i + 1])) { wellFormed = false; break; } } return wellFormed; } public static void main(String[] args) { String S = "Interview"; System.out.println("Given String – " + S); WellFormedStrings i = new WellFormedStrings(); i.wellFormedString(S); } }

Output:

```Given String - Interview
[e, e, I, i, n, r, t, v, w]
[e, e, i, I, n, r, t, v, w]
[e, e, i, I, n, r, t, v, w]
[e, e, I, i, n, r, t, v, w]

```

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