Went for Samsung Pre Employment test.
Test time was 10:30 AM - 2:30 PM
I have to visit Samsung R&D Institute India – Delhi | SRI-Delhi for this test.

1 DSA question asked.
Question = connect numbers
You are given an array of numbers A = [a0, a1, a2, a3, .... , aN]
You can connect a number a[i] with a[j] where i < j.
To connect 2 numbers the last digit of first number should be equal to first digit of second number. (refer to below examples).
A valid number is if the number first digit is same as last digit.
Find the length of max number which is valid.
1<= N <= 100,000
1 <= a[i] <= 10^9

example 1 : [14, 123, 323, 321, 431, 53635]
output = 9
explanation : valid numbers are = 14431 after joining a0 with a4, 123321 (a1 with a3), 123323321 (a1, a2, a3)
example 2 : [12, 13, 14, 15]
output = 0
example 3 = [14, 13, 22, 19]
output = 2
explanation : 22 is the valid number as first digit of number is same as last digit of number.