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ITRIX12E - R Numbers |
R - Numbers
R-numbers are numbers which have the property that they do not have the digit '0' and sum of every two adjacent digits of the number is prime. 123 is a R-number because 1+2 =3 and 2+3 =5 and 3, 5 are primes.
How many R-numbers can be formed with at most length N?
i.e. R-numbers of length 1 + R-numbers of length 2 + R-numbers of length 3 + ... R-numbers of length N.
Length of a number = Number of digits in the number.
Only four single digit numbers are R-numbers which are nothing but single digit primes 2, 3, 5, 7.
Input Specification
The first line of the input file contains T which denotes the number of test cases. The next T lines contain an integer N <= 10^9.
Output Specification
Print the numbers of R-numbers modulo 1000000007. [10^9+7];
Example
Sample Input: 2 1 2 Sample Output: 4 33
Added by: | Radhakrishnan Venkataramani |
Date: | 2012-03-12 |
Time limit: | 1s |
Source limit: | 50000B |
Memory limit: | 1536MB |
Cluster: | Cube (Intel G860) |
Languages: | All except: ASM64 |
Resource: | Own problem |
hide comments
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2012-04-17 14:42:15 (Tjandra Satria Gunawan)(曾毅昆)
Finally I got AC... @Aman Kumar: Thanks ;) |
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2012-04-10 22:12:14 Aman Kumar
@Tjandra...No.. for N=10^9 answer is.. 757510247 |
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2012-04-10 21:11:46 uzumaki_naruto
how can length of a no be 10^9?? |
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2012-04-10 04:52:49 (Tjandra Satria Gunawan)(曾毅昆)
Is the answer for N=10^9 is 498296368?? |