Number of digits in 2 raised to power n in C++

The power of a number can be computed using the iterative multiplication or function that the language provides. It's a straightforward thing.

Here, we have to find the 2 raised to power n. And the number of digits in the result. Let's see some examples.

Input

5

Output

2

Input

10

Output

4

Algorithm

• Initialise the number n.
• Find the value of 2ⁿ.
• The ceil of log10(n) will give you number of digits in the number n.
• Find it and return it.

Implementation

Following is the implementation of the above algorithm in C++

#include <bits/stdc++.h>
using namespace std;
int getDigitsCount(int n) {
   return ceil(log10(pow(2, n)));
}
int main() {
   int n = 8;
   cout << getDigitsCount(n) << endl;
   return 0;
}

Output

If you run the above code, then you will get the following result.

3