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
probeta: 2018-08-30 11:17:58

Don't use if-else since there is size limit , simply use modular expo !

rahul_gera: 2018-07-29 20:38:33

guys include the case side cases a,b=0

sktspoj: 2018-07-26 20:38:12

guys, just check the corner cases such as 10^0 = 1 , 10^1 = 0, 0^10 = 0 if you are getting wa

rajat_123: 2018-07-17 14:43:33

Last edit: 2018-07-17 14:54:26
techlicious_: 2018-06-16 23:27:38

himanshu_12345 WA=wrong answer

abhinav_313: 2018-06-16 21:10:02

how to input multiple strings separated by space.Please help

s_a_k_s_h_a_m: 2018-06-12 12:35:21

use long long and fast modular exponentation for (a^b)%10

navidator: 2018-05-31 00:31:37

If you get WA and you use modular arithmetic, there could be some issues:
1- b must be a string
2- b can be 0, but if b=0 then a != 0.

adnanlari: 2018-05-28 22:20:51

giving WA, even after considering all the cases!!

neverhopeless: 2018-04-20 12:26:36

@narutohokage_1, thanks for the pointer.

Added by:Jose Daniel Rodriguez Morales
Time limit:1s
Source limit:700B
Memory limit:1536MB
Cluster: Cube (Intel G860)
Languages:All except: GOSU