Given an integer N, the task is to find the count of natural Hexadecimal numbers with N digits.
Examples:
Input: N = 1
Output: 15Input: N = 2
Output: 240
Approach: It can be observed that for the values of N = 1, 2, 3, …, a series will be formed as 15, 240, 3840, 61440, 983040, 15728640, … which is a GP series whose common ratio is 16 and a = 15.
Hence the nth term will be 15 * pow(16, n – 1).
So, the count of n-digit natural hexadecimal numbers will be 15 * pow(16, n – 1).
Below is the implementation of the above approach:
C++
// C++ implementation of the above approach #include <bits/stdc++.h> using namespace std; // Function to return the count of n-digit // natural hexadecimal numbers int count( int n) { return 15 * pow (16, n - 1); } // Driver code int main() { int n = 2; cout << count(n); return 0; } |
Java
// Java implementation of the approach import java.io.*; class GFG { // Function to return the count of n-digit // natural hexadecimal numbers static int count( int n) { return ( int ) ( 15 * Math.pow( 16 , n - 1 )); } // Driver code public static void main(String args[]) { int n = 2 ; System.out.println(count(n)); } } // This code is contributed by 29AjayKumar |
Python3
# Python3 implementation of the above approach # Function to return the count of n-digit # natural hexadecimal numbers def count(n) : return 15 * pow ( 16 , n - 1 ); # Driver code if __name__ = = "__main__" : n = 2 ; print (count(n)); # This code is contributed by AnkitRai01 |
C#
// C# implementation of the approach using System; class GFG { // Function to return the count of n-digit // natural hexadecimal numbers static int count( int n) { return ( int ) (15 * Math.Pow(16, n - 1)); } // Driver code public static void Main(String []args) { int n = 2; Console.WriteLine(count(n)); } } // This code is contributed by 29AjayKumar |
Javascript
<script> // JavaScript implementation of the above approach // Function to return the count of n-digit // natural hexadecimal numbers function count(n) { return 15 * Math.pow(16, n - 1); } // Driver code var n = 2; document.write(count(n)); </script> |
240
Time Complexity: O(log n)
Auxiliary space: O(1), If the recursive stack is considered then it would be O(log(n))
Ready to dive in? Explore our Free Demo Content and join our DSA course, trusted by over 100,000 neveropen!