Divisible by 10
Given a stream of binary digits how can you tell if the number formed is divisible by 10.
Given an integer n, write a function that returns count of trailing zeroes in n!. Examples: Input: n = 5 Output: 1 Factorial of 5 is 20 which has one trailing 0. Input: n = 20 Output: 4 Factorial of 20 is 2432902008176640000 which has 4 trailing zeroes. Input: n = 100 Output: 24
it is divisible by 10 if it ends with 1010
ReplyDelete@gaurav i don't think it will work,check for 20,it is 10100.so it does not ends with 1010.
ReplyDeletecan u please tell the answer.i am having no clue except calculating the decimal equivalent..
ReplyDelete@kams Here's the clue :Look at powers of 2 modulo 5:
ReplyDelete2^0 = 1 = 1 mod 5
2^1 = 2 = 2 mod 5
2^2 = 4 = -1 mod 5
2^3 = 8 = -2 mod 5
2^4 = 16 = 1 mod 5
now it repeats ...
(Two numbers are equal, or more properly "congruent," modulo 5, if
they give the same remainder when they are divided by 5..now try it..:)