Suppose we have a lowercase string s with only two characters a and b. We have to check whether every group of consecutive a's is followed by group of consecutive b's of equal length.
So, if the input is like s = "abaaabbbaabbaabbab", then the output will be True, as all groups are (ab), (aaabbb), (aabb), (aabb), (ab).
To solve this, we will follow these steps −
- a_count := 0, string_len := size of s
- i := 0
- while i < string_len, do
- while i < string_len and s[i] is 'a', do
- a_count := a_count + 1
- i := i + 1
- while i < string_len and s[i] is 'b', do
- a_count := a_count - 1
- i := i + 1
- if a_count is not 0, then
- return False
- while i < string_len and s[i] is 'a', do
- return True
Example
Let us see the following implementation to get better understanding −
def solve(s): a_count = 0 string_len = len(s) i = 0 while i < string_len: while i < string_len and s[i] == 'a': a_count += 1 i += 1 while i < string_len and s[i] == 'b': a_count -= 1 i += 1 if a_count != 0: return False return True s = "abaaabbbaabbaabbab" print(solve(s))
Input
"abaaabbbaabbaabbab"
Output
True