K-th digit in ‘a’ raised to power ‘b’ in C++

In this tutorial, we are going to write a program that finds the k-th digit from the right side in the number a^b

It's a straightforward problem. Let's see the steps to solve it.

• Initialise the numbers a, b, and k.
• Find the value of a^busing pow method.
• Write a loop that iterates until power value is less than zero or count is less than k.
  • Get the last digit from the power value.
  • Increment the counter.
  • Check whether k and counter are equal or not.
  • Return the digit if they are equal
• Return -1.

Example

Let's see the code.

 Live Demo

#include <bits/stdc++.h>
using namespace std;
int getTheDigit(int a, int b, int k) {
   int power = pow(a, b);
   int count = 0;
   while (power > 0 && count < k) {
      int rem = power % 10;
      count++;
      if (count == k) {
         return rem;
      }
      power /= 10;
   }
   return -1;
}
int main() {
   int a = 5, b = 6;
   int k = 3;
   cout << getTheDigit(a, b, k) << endl;
   return 0;
}

Output

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

6

Conclusion

If you have any queries in the tutorial, mention them in the comment section.

Hafeezul Kareem

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Updated on: 09-Apr-2021

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