TheAlmostLuckyNumbers
SRM 453.5 · 2009-11-20 · by Vasyl[alphacom]
SRM 453.5 · 2009-11-20 · by Vasyl[alphacom] · Recursion
Problem Statement
Problem Statement
A lucky number is a number whose decimal representation contains only the digits 4 and 7. An almost lucky number is a number that is divisible by a lucky number. For example, 14, 36 and 747 are almost lucky, but 2 and 17 are not. Note that a number can be both lucky and almost lucky at the same time (for example, 747).
You are givenlong s a and b. Return the number of almost lucky numbers between a and b, inclusive.
You are given
Constraints
- a will be between 1 and 10,000,000,000, inclusive.
- b will be between a and 10,000,000,000, inclusive.
Examples
0)
1 10 Returns: 3
There are three almost lucky numbers less than or equal to ten - 4, 7 and 8.
1)
14 14 Returns: 1
14 is an almost lucky number.
2)
1 100 Returns: 39
3)
1234 4321 Returns: 1178
4)
1 3 Returns: 0
Submissions are judged against all 61 archived test cases, of which 5 are shown here. Case numbers match the judge’s.
Coding Area
Language: C++17 · define a public class TheAlmostLuckyNumbers with a public method long long count(long long a, long long b) · 61 test cases · 2 s / 256 MB per case