Computer Science (AS & A Level) · Oct / Nov 2021 · Paper 42 · Question 1

Study the following pseudocode for a recursive function. FUNCTION Unknown(BYVAL X, BYVAL Y : INTEGER) RETURNS INTEGER IF X < Y THEN OUTPUT X + Y RETURN (Unknown(X + 1, Y) * 2) ELSE IF X = Y THEN RETURN 1 ELSE OUTPUT X + Y RETURN (Unknown(X - 1, Y) DIV 2) ENDIF ENDIF ENDFUNCTION The operator DIV returns the integer value after division e.g. 13 DIV 2 would give 6

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