Computer Science (AS & A Level) · May / June 2025 · Paper 23 · Question 5

A module Parity() takes a string as a parameter. The parameter has the identifier BitString and it represents a binary value. The module will concatenate a single character to the end of BitString by applying one of the two rules: • '0' if Bitstring contains an even number of 1s • '1' if Bitstring contains an odd number of 1s. The modified value of BitString is then returned. For example: Parameter String returned Explanation "0010010110" "00100101100" there are an even number of 1s in the string passed to Parity() so a '0' is concatenated to the end of BitString "101010" "1010101" there are an odd number of 1s in the string passed to Parity() so a '1' is concatenated to the end of BitString Write pseudocode for the module Parity() Assume the parameter BitString can only contain the characters '0' and '1' 11 [8]

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