A magic number is defined as a number which can be expressed as a power of 5 or sum of unique powers of 5. First few magic numbers are 5, 25, 30(5 + 25), 125, 130(125 + 5), ….
Write a function to find the nth Magic number.
Input: n = 2 Output: 25 Input: n = 5 Output: 130
If we notice carefully the magic numbers can be represented as 001, 010, 011, 100, 101, 110 etc, where 001 is 0*pow(5,3) + 0*pow(5,2) + 1*pow(5,1). So basically we need to add powers of 5 for each bit set in given integer n.
Below is the implementation based on this idea.
nth magic number is 130
Thanks to manrajsingh for suggesting above solution.
This article is contributed by Abhay. Please write comments if you find anything incorrect, or you want to share more information about the topic discussed above.
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