# Replace for X SOLUTIONS REPLESX

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## Replace for X SOLUTIONS OCTOBER CHALLENGE 2020

You are given an array of N integers A1,A2,…,AN and three more integers X,p, and k.
An operation on the array is defined to be: replace the k-th smallest integer in the array with any integer you want.
Output the minimum number of operations you must perform on the array (possibly 0 operations) to make the p-th smallest element of the array equal to X. If it is impossible to do so output −1.
Note: the k-th smallest number in an array is the k-th number from the left when the array is sorted in non-decreasing order.
Input
The first line of the input contains a single integer T denoting the number of test cases. The description of T test cases follows.
The first line of each test case contains four integers N,X,p,k respectively.
The second line contains N space-separated integers A1,A2,…,AN.
Output
For each test case, print a single line containing one integer ― the minimum number of operations you must perform to make X the p-th smallest element or −1 if its impossible to do so.
Constraints
1≤T≤100
1≤p,k≤N
0≤X≤109
The sum of N over all test cases does not exceed 4∗105
0≤Ai≤109 for each valid i
Subtask #2 (40 points): The sum of N over all test cases does not exceed 3∗103
Subtask #3 (50 points): Original constraints
Example Input
2
5 4 3 4
4 9 7 0 8
2 25 1 2
100 20
Example Output
1
-1
Explanation
Example case 1:
We can perform one operation in the array. Take the k-th smallest integer of the current array (which is 8 in this case) and replace it with 0. The array then becomes [4,9,7,0,0] which now makes 4 as the 3rd smallest number of the array.
Example case 2:
It is impossible to make 25 as the smallest number of the array.

SOLUTION

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