Compress a string by replacing each run of identical consecutive characters with the character followed by the length of the run.
For example, aaabbc becomes a3b2c1.
A single line containing the string s of lower-case English letters.
The run-length encoding of s.
Example 1
aaabbc
a3b2c1
Three a, two b, one c -> a3b2c1.
Example 2
abcd
a1b1c1d1
No repeats, so every count is 1.
Example 3
zzzzz
z5
A single run of five z.
Scan left to right and group equal characters that sit next to each other.
For each group, output the character once and then how many times it repeated (always include the count, even when it is 1).
Walk the string, extending a run while the next character matches. When it changes, emit the character and the run length, then start a new run.
s = input()
res = []
i = 0
while i < len(s):
j = i
while j < len(s) and s[j] == s[i]:
j += 1
res.append(s[i] + str(j - i))
i = j
print("".join(res))
Tell us what needs to change, who it affects and any important deadline. We will review the context and reply with useful next questions.