LASTDIG - The last digit

Nestor was doing the work of his math class about three days but he is tired of make operations a lot and he should deliver his task tomorrow. His math’s teacher gives him two numbers a and b. The problem consist of finding the last digit of the potency of base a and index b. Help Nestor with his problem. You are given two integer numbers: the base a (0 <= a <= 20) and the index b (0 <= b <= 2,147,483,000), a and b both are not 0. You have to find the last digit of ab.


The first line of input contains an integer t, the number of test cases (t <= 30). t test cases follow. For each test case will appear a and b separated by space.


For each test case output an integer per line representing the result.


3 10
6 2

Output: 9 6

hide comments
dhruv19: 2016-12-20 14:55:46

@koko4nut please help me i am getting a TLE how can i optimize my code

tejman1809: 2016-12-16 15:26:54

@koko4nut Thank You, but what exactly is the mistake because of which its not getting accepted?

koko4nut: 2016-12-16 09:24:21

@tejman1809 . Your test is successful returning "0" when a = b = 0.
Or this operation is not permitted like a division by 0.
And indent properly your code! for your own good and others!!!
It felt like having nails scratching my eye balls.

Last edit: 2016-12-16 09:30:00
tejman1809: 2016-12-16 08:20:30

Can someone please check what's wrong with my code?Already received 12 WAs.
Link:[spoiler removed ; please use forum in the future]

Last edit: 2016-12-16 18:50:46
koko4nut: 2016-12-15 22:21:50

I got a runtime error (NZEC) but run just fine at home and on ideone.[spoiler removed]
Any idea?

Last edit: 2016-12-16 18:51:52
yash_code_guy: 2016-12-15 19:38:16

I used the logic that the last digit that we will get from a^b will be same as that we will get from a^m where m=b%4
I dont know why am i getting a WA

darpanjbora: 2016-12-13 16:17:55

AC in one go with Java. ;)

keshavsharma: 2016-12-11 19:46:14

getting time limit exceed :(

aditya930: 2016-12-09 05:58:01

#50....easy question AC in one go!

spartax: 2016-11-24 14:55:09

trivial. I did in theta(t) time complexity

Added by:Jose Daniel Rodriguez Morales
Time limit:0.340s
Source limit:700B
Memory limit:1536MB
Cluster: Cube (Intel G860)