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 a^{b}.
Input
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.
Output
For each test case output an integer per line representing the result.
Example
Input: 2 3 10 6 2
Output: 9 6
hide comments
keshavsharma:
20161211 19:46:14
getting time limit exceed :( 

aditya930:
20161209 05:58:01
#50....easy question AC in one go!


spartax:
20161124 14:55:09
trivial. I did in theta(t) time complexity 

pratik97:
20161104 13:52:14
modular exponentiation


esshuvo:
20161024 14:02:56
you can't get AC without getting some "error" :) 

sreekanthkol:
20161016 11:55:31
@timmy jose how do you generate your own test cases? I mean is there a tool that automatically does that? 

sreekanthkol:
20161016 11:53:07
@mhto you missed the corner case of b =0 

sreekanthkol:
20161016 11:30:13
@filip sollar the problem is simpler than you think. You used a for loop, no need to do that. I could tell you how but I don't want to spoil it for you. 

Filip Sollar:
20161014 02:44:44
can anyone help me ? solved using modular exponention even checked for case when b == 0 so my program doesnt crash but getting WA https://ideone.com/QGqclL 

srihari_v:
20161007 20:59:27
no need of any bigmod algorithm

Added by:  Jose Daniel Rodriguez Morales 
Date:  20081201 
Time limit:  1s 
Source limit:  700B 
Memory limit:  1536MB 
Cluster:  Cube (Intel G860) 
Languages:  All except: GOSU 
Resource:  Own 