Watch 10 video solutions for String Compression, a medium level problem involving Two Pointers, String. This walkthrough by Kevin Naughton Jr. has 97,097 views views. Want to try solving it yourself? Practice on FleetCode or read the detailed text solution.
Given an array of characters chars, compress it using the following algorithm:
Begin with an empty string s. For each group of consecutive repeating characters in chars:
1, append the character to s.The compressed string s should not be returned separately, but instead, be stored in the input character array chars. Note that group lengths that are 10 or longer will be split into multiple characters in chars.
After you are done modifying the input array, return the new length of the array.
You must write an algorithm that uses only constant extra space.
Example 1:
Input: chars = ["a","a","b","b","c","c","c"] Output: Return 6, and the first 6 characters of the input array should be: ["a","2","b","2","c","3"] Explanation: The groups are "aa", "bb", and "ccc". This compresses to "a2b2c3".
Example 2:
Input: chars = ["a"] Output: Return 1, and the first character of the input array should be: ["a"] Explanation: The only group is "a", which remains uncompressed since it's a single character.
Example 3:
Input: chars = ["a","b","b","b","b","b","b","b","b","b","b","b","b"] Output: Return 4, and the first 4 characters of the input array should be: ["a","b","1","2"]. Explanation: The groups are "a" and "bbbbbbbbbbbb". This compresses to "ab12".
Constraints:
1 <= chars.length <= 2000chars[i] is a lowercase English letter, uppercase English letter, digit, or symbol.