spoj#SUBXOR. SubXor
SubXor
A straightforward question. Given an array of positive integers you have to print the number of subarrays whose XOR is less than K. Subarrays are defined as a sequence of continuous elements Ai, Ai+1, ..., Aj . XOR of a subarray is defined as Ai ^ Ai+1 ^ ... ^ Aj. Symbol ^ is Exclusive Or. You can read more about it here:
http://en.wikipedia.org/wiki/Exclusive_or
Input Format:
First line contains T, the number of test cases. Each of the test case consists of N and K in one line, followed by N space separated integers in next line.
Output Format:
For each test case, print the required answer.
Constraints:
1 ≤ T ≤ 10
1 ≤ N ≤ 10^5
1 ≤ A[i] ≤ 10^5
1 ≤ K ≤ 10^6
Sum of N over all testcases will not exceed 10^5.
Sample Input:
1 5 2 4 1 3 2 7
Sample Output:
3
Explanation:
Only subarrays satisfying the conditions are [1], [1,3,2] and [3,2].
Problem Setter: Lalit Kundu