I'm the CTO at a startup in London, so I'm spending a lot of my time interviewing developers as we try to grow our team. As part of that, I ask each of them to do what I consider to be a very simple programming exercise (See below.)
Yet, the results of this are disappointing. About 10% of candidates will be able to produce a solution in 10 minutes or less, another 30% of candidates will eventually produce something close to a solution in 30 minutes (though often with errors), and 60% of candidates will simply be unable to produce anything close to a solution. These are not junior or graduate developers, but senior, experienced programmers asking for £50k or £60k.
I try to make the candidates as comfortable as possible while doing this, but even so, the inability of 90% of the people I interview to develop a solution to a simple question is astonishing.
Am I being too hard on the candidates in asking them to do this?
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This is, verbatim, the problem sheet I show them:
Pascal’s Triangle
Each element in Pascal’s Triangle is found by adding the two numbers to the right and left of it on the row above it; where these don’t exist, they are assumed to be zero.
1
1 1
1 2 1
1 3 3 1
1 4 6 4 1
1 5 10 10 5 1
(This is correctly centered in the actual document.)
Write a function that takes a single integer n as a parameter and returns the nth row of Pascal’s Triangle.
For example:
pascal(1) should return [1]
pascal(4) should return [1, 3, 3, 1]
Yet, the results of this are disappointing. About 10% of candidates will be able to produce a solution in 10 minutes or less, another 30% of candidates will eventually produce something close to a solution in 30 minutes (though often with errors), and 60% of candidates will simply be unable to produce anything close to a solution. These are not junior or graduate developers, but senior, experienced programmers asking for £50k or £60k.
I try to make the candidates as comfortable as possible while doing this, but even so, the inability of 90% of the people I interview to develop a solution to a simple question is astonishing.
Am I being too hard on the candidates in asking them to do this?
-------------------------------------------------------------------
This is, verbatim, the problem sheet I show them:
Pascal’s Triangle
Each element in Pascal’s Triangle is found by adding the two numbers to the right and left of it on the row above it; where these don’t exist, they are assumed to be zero.
1
1 1
1 2 1
1 3 3 1
1 4 6 4 1
1 5 10 10 5 1
(This is correctly centered in the actual document.)
Write a function that takes a single integer n as a parameter and returns the nth row of Pascal’s Triangle.
For example:
pascal(1) should return [1]
pascal(4) should return [1, 3, 3, 1]