Leetcode problem 1409:- Queries on a Permutation With Key

Given the array queries of positive integers between 1 and m, you have to process all queries[i] (from i=0 to i=queries.length-1) according to the following rules:

In the beginning, you have the permutation P=[1,2,3,...,m].
For the current i, find the position of queries[i] in the permutation P (indexing from 0) and then move this at the beginning of the permutation P. Notice that the position of queries[i] in P is the result for queries[i].

Return an array containing the result for the given queries.

Example 1:

Input: queries = [3,1,2,1], m = 5
Output: [2,1,2,1]
Explanation: The queries are processed as follow:
For i=0: queries[i]=3, P=[1,2,3,4,5], position of 3 in P is 2, then we move 3 to the beginning of P resulting in P=[3,1,2,4,5].
For i=1: queries[i]=1, P=[3,1,2,4,5], position of 1 in P is 1, then we move 1 to the beginning of P resulting in P=[1,3,2,4,5].
For i=2: queries[i]=2, P=[1,3,2,4,5], position of 2 in P is 2, then we move 2 to the beginning of P resulting in P=[2,1,3,4,5].
For i=3: queries[i]=1, P=[2,1,3,4,5], position of 1 in P is 1, then we move 1 to the beginning of P resulting in P=[1,2,3,4,5].
Therefore, the array containing the result is [2,1,2,1].

Example 2:

Input: queries = [4,1,2,2], m = 4
Output: [3,1,2,0]

Example 3:

Input: queries = [7,5,5,8,3], m = 8
Output: [6,5,0,7,5]

Flow Diagram: –

Solution:-

class Solution {
    public int[] processQueries(int[] queries, int m) {
      int noOfQueries=queries.length;
        int[] answer=new int[noOfQueries];
        LinkedList queriesList=new LinkedList<>();
        for(int index=1;index<=m;index++)
        {
            queriesList.add(index);
          
        }
        for(int index=0;index<noOfQueries;index++)
        {
            int value=queries[index];
            int reqIndex=queriesList.indexOf(value);
           
            queriesList.remove(reqIndex);
            queriesList.addFirst(value);
            answer[index]=reqIndex;
        }
        return answer;


    }
    }