Question

I need to print the first k digits and the last k digits in

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n^n (n to the power of n, where n is an integer)
For example :

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Input       Output

n k         First k digits       Last k digits

4 2    -->  25                   56
9 3    -->  387                  489

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I sense that it requires some clever mathematics, however I am unable to think of anything as such. Please suggest a way to approach the problem.

Answer 1

The last k digits are easy, you just need to calculate it modulo 10^k. To do this, after every multiplication, just apply the modulo, ie. intermediate_result %= 10^k.

Of course, you will need to calculate 10^k using some other method, because ^ does not mean power of in C or Java.

To find the first k digits, see first n digits of an exponentiation.