Find Total Number of Strings with Unique Characters in Python

Suppose we have a string s of lowercase letters, we have to find the total number of substrings that contain one unique character.

So, if the input is like "xxyy", then the output will be 6 as substrings are [x, x, xx, y, y, yy]

To solve this, we will follow these steps −

• total := 0
• previous := blank string
• for each character c in s, do
  • if c is not same as previous, then
    • previous := c
    • temp := 1
  • otherwise,
    • temp := temp + 1
  • total := total + temp
• return total

Let us see the following implementation to get better understanding −

Example

 Live Demo

class Solution:
   def solve(self, s):
      total = 0
      previous = ''
      for c in s:
         if c != previous:
            previous = c
            in_a_row = 1
         else:
            in_a_row += 1
            total += in_a_row
      return total
ob = Solution()
print(ob.solve("xxyy"))

Input

"xxyy"

Output

6