**Algorithms** – **Rearrange the Array of Given Range N, such that A[i]=i. **

**Objective: **Given a array of length N, in which elements are in the range of 1 to N. All elements may not present in the array. If element is not present , there will be -1 present in the array. Rearrange the array such that A[i]=i and if i is not present, display -1 at that place. See example

**Example****: **

**Approach: – Time Complexity -O(N), Space Complexity – O(1)**

- Navigate the array.
- Check if element is -1, if yes then ignore it.
- If element is not -1, Check if its at it
If yes then ignore it.*correct position (i=A[i]),* - If element is not -1, and element is not at its correct
then We need to place it to its correct position but there are two conditions*position (i!=A[i])*- Either
, means*A[i] is vacate*, then just put*A[i]=-1**A[i]=i .* - OR
, means*A[i] is not vacate*, then*A[i]=x*put*int y=x*. Now we need to place*A[i]=i*to its correct place, so repeat from step 3. .*y*

- Either

**Code:**

https://gist.github.com/thmain/63ed52e6de57dd2cb177

**Output**:

Fixed Indexed Array [-1, 1, 2, 3, 4, -1, 6, -1, -1, 9] Fixed Indexed Array [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19]