69. Squash the Runs
A compression tool shortens a string by replacing every run, a maximal block of one repeated character, with that character followed by the length of the run written in decimal. A run of length 1 is also written with its count.
Given the string s, return its compressed form. For example, "aaab" becomes "a3b1". Runs longer than 9 use all their digits.
Example 1
- Input:
- s = "wwwxyy"
- Output:
- "w3x1y2"
- Explanation:
The runs are www, x and yy, which are written as w3, x1 and y2.
Example 2
- Input:
- s = "kkkkkkkkkkkk"
- Output:
- "k12"
- Explanation:
One run of twelve k characters is written as k12.
Constraints
1 ≤ s.length ≤ 105
s contains only lowercase English letters
How this problem is judged
- Answers
- Your answer must match exactly. Numbers compare by value, so 2 and 2.0 are equal.
Expected complexity
- Time
- O(n)
- Space
- O(n)