Python Lists, Gates, and Interrupts | Dataford Interview Questions

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Arm firmware often manipulates compact signal arrays and selects logic paths through multiplexers. Implement a simulator that applies requested swaps to an integer list and evaluates Boolean gates using only a 2:1 MUX abstraction.

Formal Specification

Write process_signals(values, swaps, gates).

values is a list of integers.
Each swap is [i, j, method], where method is either "temp" or "xor". Swap values[i] and values[j] in place. The "temp" method must use a temporary variable. The "xor" method must swap using XOR without a third variable. Assume i != j.
Each gate is [name, a, b], where name is "NOT", "AND", "OR", or "XOR", and a and b are Boolean integers, either 0 or 1. For NOT, ignore b.
Model a 2:1 MUX as mux(select, input0, input1), which returns input0 when select == 0 and input1 when select == 1.
Construct every gate from MUX calls, rather than using the corresponding Python Boolean operator directly.
Return a dictionary with the final list under "values" and gate results, in input order, under "gates".

Constraints

1 <= len(values) <= 10^4
0 <= len(swaps), len(gates) <= 10^4
Every swap index is valid and distinct
List values fit within signed 32-bit integers
Gate inputs are restricted to 0 and 1

Function Signature

def process_signals(values, swaps, gates):