### adding 1 and -1 || invalid operation return 0 -

All programs should be one line long!
Long live the Magical Python One-Liner!!

Code
Diff
• ``````basicOp=lambda o,v,w:v/w if o=='/'else{'+':v+w,'-':v-w,'*':v*w}[o]if o in'+-*'else"Invalid Operation"
# Python one-liners are turing-complete, so why would you ever use more than that?``````
• def basicOp(operation, value1, value2):
• if operation == "+":
• return value1 + value2
• if operation == "-":
• return value1 - value2
• if operation == "*":
• return value1 * value2
• if operation == "/":
• return value1 / value2
• return "Invalid Operation"
• basicOp=lambda o,v,w:v/w if o=='/'else{'+':v+w,'-':v-w,'*':v*w}[o]if o in'+-*'else"Invalid Operation"
• # Python one-liners are turing-complete, so why would you ever use more than that?

### Euler's Totient Function

Code
Diff
• ``````def factorise(a): # takes much less than O(a), unless a is prime
prime_factors = {}
p = 1
while a > 1:
p += 1
while a % p == 0:
if p in prime_factors: prime_factors[p] += 1
else: prime_factors[p] = 1
a = a//p
return prime_factors

def totient(a):
"""python 3.6.0"""
primes = factorise(a)
totient = 1
for i in primes: # formula for totient from prime factorisation
totient *= i**(primes[i]-1) * (i-1)
• from math import gcd
• def factorise(a): # takes much less than O(a), unless a is prime
• prime_factors = {}
• p = 1
• while a > 1:
• p += 1
• while a % p == 0:
• if p in prime_factors: prime_factors[p] += 1
• else: prime_factors[p] = 1
• a = a//p
• return prime_factors
• def totient(a):
• """python 3.6.0"""
• return len([b for b in range(a) if (gcd(a, b) == 1)])
• primes = factorise(a)
• totient = 1
• for i in primes: # formula for totient from prime factorisation
• totient *= i**(primes[i]-1) * (i-1)