Too many solvers not providing additional problems!
Here’s another… Assuming you have an array of numeric data, write a
method that returns an array of progressive sums. That is:
prog_sum( [1, 5, 13, -6, 20] ) => [1, 6, 19, 13, 33]On Monday 22 September 2008 23:26:34 Martin DeMello wrote:
On Mon, Sep 22, 2008 at 2:07 PM, Matthew M. [email protected]
wrote:Too many solvers not providing additional problems!
Here’s another… Assuming you have an array of numeric data, write a
method that returns an array of progressive sums. That is:prog_sum( [1, 5, 13, -6, 20] ) => [1, 6, 19, 13, 33]
def prog_sum(ary)
ary.inject([0, []]) {|(s, a), i| [s+i, a<<(s+i)]}.last
end
And what about
def prog_sum(array)
sum = 0; array.collect { |e| sum+=e }
end
class Array
def to_s
collect{|x| x.to_s.gsub(/\n/,"\n| “)}.join(”\n|-- ")
end
end
puts [:foo, [:bar, [:baz, :quux], :hello, :world], :done].to_s
Works fine for given example but fails for example with
puts [:a, [:b, :c]].to_s
a
|-- b
| |-- c
Still working on this…
New question
Write a oneliner next_fib(n) which gives the smallest Fibonacci number
greater than n
2008/9/22 Martin DeMello [email protected]
Summary coming late today.
Technically not one line, but it’s under 80 chars and is recursive…
def f n;self.zip(n==2?self:f(n-1));end;def repeat n;f(n).flatten;end
…doesn’t work for n < 2
Offered quiz is a no-brainer; mostly for golfing…
Given an epsilon, compute PI to that precision.
Todd
Matthew M. [email protected] wrote:
New challange:
Starting with an array, find the first permutation of the elements of
that array that is lexicographically greater than (i.e. sorts after)
the given array.I was tempted to port the C++ next_permutation code, but then I
realized I have class.
I’ve done it, and posted it here, but It’s not one line. I’m not sure
if that’s even doable.
What I do know is that most permutation generators in Ruby just look
at positions, not data, and by doing so, they yield identical
permutations in a single iteration when there are indentical data
elements.
–Ken