• 24

## Goal

Although ternary computing has fallen out of favor these last 40 years or more, there is reason to think that it may be an important part of the future. Whereas each digit in a binary system has two possible states, ternary digits have three possible states. In the Balanced Ternary system, each digit represents either -1, 0, or +1.

In binary, each digit is worth its face value (1 or 0) multiplied by a power of two determined by its position:

Binary
┌──────> 1 * (2^3) = 8│┌─────> 1 * (2^2) = 4││┌────> 0 * (2^1) = 0│││┌───> 1 * (2^0) = 11101               = 13

In Balanced Ternary, the system is similar except each value (-1, 0, or +1) is multiplied by a power of 3 determined by its position. "1" and "0" represent themselves and "T" represents -1 (it sort of looks like "-1", right?):

Balanced Ternary
┌───────> +1 * (3^4) = 81│┌──────> -1 * (3^3) = -27││┌─────>  0 * (3^2) = 0│││┌────> +1 * (3^1) = 3││││┌───> -1 * (3^0) = -11T01T                = 56

In order to be able to use Balanced Ternary, we need to be able to do some rudimentary operations. You must develop an application that can evaluate expressions using five binary operators: left shift, right shift, addition, subtraction, and multiplication. The shift operators do not wrap. Some examples:

Examples
1T0 >> 1 = 1T1T0 >> 1T = 11T0 << 1 = 1T001T0 + 1 = 1T11T1 + 1 = 10T1T0 - 1 = 1TT1T * 1T = 11

Note: You may want to complete the easier related puzzle first: https://www.codingame.com/training/easy/balanced-ternary-computer-encode
Input
Line 1: The first operand, lhs.
Line 2: The operator, op.
Line 3: The second operand, rhs.
Output
A single line containing the evaluation of the input expression in Balanced Ternary, ret.
Constraints
In Decimal:
-3280 <= lhs <= 3280
-3280 <= rhs <= 3280
-3280 <= ret <= 3280
In Balanced Ternary:
TTTTTTTT <= lhs <= 11111111
TTTTTTTT <= rhs <= 11111111
TTTTTTTT <= ret <= 11111111

op is one of +, -, >> , << , *.
Example
Input
1T1
+
11
Output
11T

A higher resolution is required to access the IDE

Join the CodinGame community on Discord to chat about puzzle contributions, challenges, streams, blog articles - all that good stuff!
Online Participants