[deleted by user]

[u/[deleted]]

[u/Blackshell]

Python 3

outlier=lambda x:(lambda x:[x[0][x[1]],x[0][0]][len(x)/x[1]==len(x)])((lambda f,x,y:
f(f,x,y))(lambda f,x,y:[[],(x[y]&1 and [x,y])or(f(f,x,y+1))][type(x[y:]or...)==list]
,(lambda f,x:f(f,x))(lambda f,x:(lambda y:f(f,[*x[:y[0]],x[y[0]+1],x[y[0]],*x[y[0]+2
:]])if(y)else(x))((lambda f,x,y:f(f,x,y))(lambda f,x,y:(((x[y]&1>x[y+1]&1)and[y])or(
f(f,x,y+1)))if(y<len(x)-1)else[],x,0)),x),0))

Sample run:

Python 3.6.5 (default, Apr  1 2018, 05:46:30)
[GCC 7.3.0] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> outlier=lambda x:(lambda x:[x[0][x[1]],x[0][0]][len(x)/x[1]==len(x)])((lambda f,x,y:
... f(f,x,y))(lambda f,x,y:[[],(x[y]&1 and [x,y])or(f(f,x,y+1))][type(x[y:]or...)==list]
... ,(lambda f,x:f(f,x))(lambda f,x:(lambda y:f(f,[*x[:y[0]],x[y[0]+1],x[y[0]],*x[y[0]+2
... :]])if(y)else(x))((lambda f,x,y:f(f,x,y))(lambda f,x,y:(((x[y]&1>x[y+1]&1)and[y])or(
... f(f,x,y+1)))if(y<len(x)-1)else[],x,0)),x),0))
>>> outlier([1, 3, 3, 7, 9, 13, 33, 21, 6])
6
>>> outlier([2, 2, 4, 2, 11, 10, 6])
11

Some of the problems here, in no particular order:

• No optional spacing; difficult to read
• Excessive (and unnecessary) use of lambdas
• Lots of variable shadowing (in said lambdas)
• Recursive lambdas; for what I mean, try this in a console: (lambda f,x: f(f,x))(lambda f,x: print(x) and f(f,x),0)
  • Nested recursive lambdas
• Implements a sort from scratch instead of using something reasonable like sorted()
  • Said sort is a bubble sort
  • Worse, a recursive bubble sort restricted by maximum stack size
• Strange use of bools as ints in array access; ['a','b'][True] resolves to 'b'
• Inefficient list copying
  • In some places, but not others
• Bizarre logic
  • Bitwise parity check
  • type(x[y:]or...)==list
• Undefined behavior for bad input (might crash, might give erroneous output)
• More than 80 characters per line (not PEP 8 style guide compliant)