Puzzle Corner
Vector 5:3, page 19
Transcribed from the printed issue; not yet reviewed. Read it in the PDF of the issue, page 19
Professor A.P.Ellis looked anxiously at his watch and then at his APL terminal. There in front of him was the 50 by 8 matrix of the end-of-term marks, which had to be converted from percentages to grades in the next few minutes so that he could stick the results up on the notice board.
Muttering into his beard to the effect that he couldn’t see why he should not give the students the actual percentages instead of grades A (70 or over), B (60 to 69),C (50 to 59) D (40 to 49), E (35 to 39 ) and F (34 or under) he suddenly realised how easy it was to do the whole operation of converting the number matrix of percentages to a character matrix of grades in APL.
Swiftly he typed at the keyboard, and before you could say ‘quick basic’ the required character matrix appeared on the screen. How do you think he did it?