FiveProb.py

"""
http://www.shiftedup.com/2015/05/07/five-programming-problems-every-software-engineer-should-be-able-to-solve-in-less-than-1-hour
"""
from functools import reduce
from operator import add

def sol1(seq):
    ans = [0 , 0 , 0]
    for it in seq:
        ans[0] += it

    i = 0
    while i < len(seq):
        ans[1] += seq[i]
        i += 1

    ans[2] = (lambda f , *cond: f(f , *cond)) \
            (lambda f , l , acc: f(f , l[1::] , acc + l[0]) if l else acc , seq , 0)

    return (all([e == sum(seq) for e in ans]) , ans)

def sol2(a , b):
    return reduce(add , zip(a , b))

def sol3(l):
    return reduce(lambda acc , i: acc + [acc[i - 2] + acc[i - 1]] , range(2 , l) , [0 , 1])

def sol4(ls):
    return ''.join(reversed(sorted([str(e) for e in ls])))

def sol5(exp , po):
    inserted = lambda exp , po , elt: exp[:po:] + elt + exp[po::]
    solved = lambda op: sol5(inserted(exp , po , op) , po + len(op) + 1)
    return reduce(add , map(solved , ('+' , '-' , ''))) \
            if po < len(exp) else ([exp] if eval(exp) == 100 else [])

print(sol1([1 , 3 , 5 , 7 , 9]))
print(sol2([1 , 2 , 3] , ['a' , 'b' , 'c']))
print(sol3(100))
print(sol4([50 , 2 , 1 , 9]))
print(sol5("123456789" , 1))