Calculating the sum of a sequence of consecutive numbers
In February there was a post on Linkedin which contained a question from an interview and sort comment. The question
stipulated that an Assembler program be written to calculate the sum of a sequence of numbers, i.e. 1,2,3,4,5,6,7, to n,
but that there was to be no loop.
Initially I saw the lack of iterative processing as a problem, but then somebody posted a formula sum = (n * (n+1))/2.
It dawned on me that the exercise is useful in demonstrating various techniques in different languages so these are some
offerings for edification and delight.
Original version |
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Modified version |
These examples address the question directly, accepting the sequence end number as input but without any data validation. |
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These examples accept two numbers representing the start and end of the sequence, and the numbers are validated. |