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

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Taras Brzezinsky: 2012-09-14 17:36:48

0^0 can mean 10^0, 'cause 10=0 mod 10
u nead only to know a^b mod 10, where a=0..9 and b=1...4 cause phi(10)=4

J├╝rgen Boger: 2012-09-14 17:36:48

Hey, i got several runtime exceptions (NZEC) in my C# code. Afterward i figured out, that SPOJ doesn't know the "continue" command. After placing some brackets, so that my code works without "continue", i got AC.

Efim: 2012-09-14 17:36:48

send your solution as file. not as text.

Lakshmeepathi G: 2012-09-14 17:36:48

However small I write the program(eliminating even the newline character),the size is coming closely to 1000B and is not getting accepted(SPOJ says : ERROR)
Any Suggestions Please?

Gagan Singhal: 2012-09-14 17:36:48

Finally solved it.!!Silly mistakes!!

Last edit: 2009-12-18 14:58:29
Muhammad Ridowan: 2012-09-14 17:36:48

Or better you could lower the time limit, in which no Bigi can solve it. ;)

Drew Saltarelli: 2012-09-14 17:36:48

you should limit the languages to only those that don't have built in arbitrary big numbers :D

nthrgeek: 2012-09-14 17:36:48

No it's not,if know basic math

Last edit: 2009-08-04 11:09:32
Sura: 2012-09-14 17:36:48

This problem is very challenging with Java lengthy programming ;)

Ambuj Varshney: 2012-09-14 17:36:48

for 0^0 solution is 1 , need to add explicitly. Otherwise , judge will show Wrong Answer.

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