36. differentSymbolsNaive

Task

Given a string, find the number of different characters in it.

Example

For s = "cabca", the output should be
differentSymbolsNaive(s) = 3.

There are 3 different characters a, b and c.

Input/Output

• [execution time limit]
  4 seconds (py3)

• [input] string s
  A string of lowercase English letters.
  Guaranteed constraints: 3 ≤ s.length ≤ 1000.

• [output] integer

My Solution

def differentSymbolsNaive(s):
    existChar = []
    count = 0
    for letter in s:
        if letter not in existChar:
            existChar.append(letter)
            count += 1
    return count