2014-09-11

Problem 016: Power digit sum

Description:

2^15 = 32768 and the sum of its digits is 3 + 2 + 7 + 6 + 8 = 26.

What is the sum of the digits of the number 2^1000?

Solution:
v00000000000000000000000000000000000000000000000000000000000
v00000000000000000000000000000000000000000000000000000000000
v00000000000000000000000000000000000000000000000000000000000
v00000000000000000000000000000000000000000000000000000000000
v00000000000000000000000000000000000000000000000000000000000
v00000000000000000000000000000000000000000000000000000000001

> "0":::::00p01p02p03p04p05p v  // INIT
v  p64*8"}"p60*p62:6p61:"<"  <v p66-1g66                <
>06g1-66p             0> 66g16g%66g16g/g"0"-+ 66g|
v      \$#                            <                  .
>46g:!#^_ 1-46p 06g1-66p 076p > 66g!#^_  v              @
v61g66+"0"%+55:+g67*2-"0"g/g61 g66%g61g66<
>g%66g16g/p55+/76p 66g1-66p   ^
Start
??
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Output:
Stack:   (0)

Explanation:

Here I implemented a long multiplication algorithm. Then I took the value `1` and doubled it 1000 times. The calculation of the digit sum was then easy.

 Interpreter steps: 27 332 672 Execution time (BefunExec): 4.23s (6.46 MHz) Program size: 60 x 14 (fully conform befunge-93) Solution: 1366 Solved at: 2014-09-11

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